Science.gov

Sample records for modified maize zea

  1. Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

    PubMed

    Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

    2016-04-01

    This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea maysL.) on growth and germination of succeeding crop wheat (Triticum aestivumL.) and associated weed (Avena fatuaL.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatuaL.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. PMID:24215059

  2. 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. PMID:25300834

  3. 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. PMID:25300835

  4. Randomly Detected Genetically Modified (GM) Maize (Zea mays L.) near a Transport Route Revealed a Fragile 45S rDNA Phenotype

    PubMed Central

    Waminal, Nomar Espinosa; Ryu, Ki Hyun; Choi, Sun-Hee; Kim, Hyun Hee

    2013-01-01

    Monitoring of genetically modified (GM) crops has been emphasized to prevent their potential effects on the environment and human health. Monitoring of the inadvertent dispersal of transgenic maize in several fields and transport routes in Korea was carried out by qualitative multiplex PCR, and molecular analyses were conducted to identify the events of the collected GM maize. Cytogenetic investigations through fluorescence in situ hybridization (FISH) of the GM maize were performed to check for possible changes in the 45S rDNA cluster because this cluster was reported to be sensitive to replication and transcription stress. Three GM maize kernels were collected from a transport route near Incheon port, Korea, and each was found to contain NK603, stacked MON863 x NK603, and stacked NK603 x MON810 inserts, respectively. Cytogenetic analysis of the GM maize containing the stacked NK603 x MON810 insert revealed two normal compact 5S rDNA signals, but the 45S rDNA showed a fragile phenotype, demonstrating a “beads-on-a-string” fragmentation pattern, which seems to be a consequence of genetic modification. Implications of the 45S rDNA cluster fragility in GM maize are also discussed. PMID:24040165

  5. Proteome Profile of the Developing Maize (Zea mays L.) Rachis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection of the developing maize (Zea mays L.) ear with the pathogenic fungus Aspergillus flavus, which produces the carcinogen aflatoxin, is a serious agricultural problem causing significant economic losses worldwide. The rachis (or cob) is an important structure that fungus uses to spread within...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Biosorption of lead by maize (Zea mays) stalk sponge.

    PubMed

    García-Rosales, G; Colín-Cruz, A

    2010-11-01

    This study investigated the removal of Pb(II) from aqueous solutions by a maize (Zea mays) stalk sponge. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of the contact time and concentration at the optimum pH of 6 +/- 0.2. The Freundlich model was found to describe the sorption energetics of Pb(II) by Z. mays stalk sponge, and a maximum Pb(II) loading capacity of 80 mg g(-1) was determined. The kinetic parameters were obtained by fitting data from experiments measuring the effect of contact time on adsorption capacity into pseudo-first and second-order equations. The kinetics of Pb(II) sorption onto Z. mays biosorbent were well defined using linearity coefficients (R(2)) by the pseudo-second-order equation (0.9998). The results obtained showed that Zea may stalk sponge was a useful biomaterial for Pb(II) sorption and that pH has an important effect on metal biosorption capacity. PMID:20615602

  8. Sugar Efflux from Maize (Zea mays L.) Pedicel Tissue 1

    PubMed Central

    Porter, Gregory A.; Knievel, Daniel P.; Shannon, Jack C.

    1985-01-01

    Sugar release from the pedicel tissue of maize (Zea mays L.) kernels was studied by removing the distal portion of the kernel and the lower endosperm, followed by replacement of the endosperm with an agar solute trap. Sugars were unloaded into the apoplast of the pedicel and accumulated in the agar trap while the ear remained attached to the maize plant. The kinetics of 14C-assimilate movement into treated versus intact kernels were comparable. The rate of unloading declined with time, but sugar efflux from the pedicel continued for at least 6 hours and in most experiments the unloading rates approximated those necessary to support normal kernel growth rates. The unloading process was challenged with a variety of buffers, inhibitors, and solutes in order to characterize sugar unloading from this tissue. Unloading was not affected by apoplastic pH or a variety of metabolic inhibitors. Although p-chloromercuribenzene sulfonic acid (PCMBS), a nonpenetrating sulfhydryl group reagent, did not affect sugar unloading, it effectively inhibited extracellular acid invertase. When the pedicel cups were pretreated with PCMBS, at least 60% of sugars unloaded from the pedicel could be identified as sucrose. Unloading was inhibited up to 70% by 10 millimolar CaCl2. Unloading was stimulated by 15 millimolar ethyleneglycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid which partially reversed the inhibitory effects of Ca2+. Based on these results, we suggest that passive efflux of sucrose occurs from the maize pedicel symplast followed by extracellular hydrolysis to hexoses. Images Fig. 1 Fig. 2 PMID:16664091

  9. Acetolactate Synthase Activity in Developing Maize (Zea mays L.) Kernels

    PubMed Central

    Muhitch, Michael J.

    1988-01-01

    Acetolactate synthase (EC 4.1.3.18) activity was examined in maize (Zea mays L.) endosperm and embryos as a function of kernel development. When assayed using unpurified homogenates, embryo acetolactate synthase activity appeared less sensitive to inhibition by leucine + valine and by the imidazolinone herbicide imazapyr than endosperm acetolactate synthase activity. Evidence is presented to show that pyruvate decarboxylase contributes to apparent acetolactate synthase activity in crude embryo extracts and a modification of the acetolactate synthase assay is proposed to correct for the presence of pyruvate decarboxylase in unpurified plant homogenates. Endosperm acetolactate synthase activity increased rapidly during early kernel development, reaching a maximum of 3 micromoles acetoin per hour per endosperm at 25 days after pollination. In contrast, embryo activity was low in young kernels and steadily increased throughout development to a maximum activity of 0.24 micromole per hour per embryo by 45 days after pollination. The sensitivity of both endosperm and embryo acetolactate synthase activities to feedback inhibition by leucine + valine did not change during kernel development. The results are compared to those found for other enzymes of nitrogen metabolism and discussed with respect to the potential roles of the embryo and endosperm in providing amino acids for storage protein synthesis. PMID:16665871

  10. A linkage map of maize x teosinte zea luxurians and identification of qtls controlling root aerenchyma formation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One-hundred and ninety five F2 individuals, derived from a cross between maize inbred line B73 x Zea luxurians, were subjected to a 107 SSR marker based QTL analysis for aerenchyma cell formation that covered 1,331 cM across all ten maize and Zea luxurians chromosomes. Composite interval mapping a...

  11. A cellular study of teosinte Zea mays ssp. parviglumis (Poaceae) caryopsis development showing several processes conserved in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although recent molecular studies elucidate the genetic background leading to changed morphology of maize female inflorescence and the structure of the caryopsis during the domestication of maize (Zea mays ssp. mays) from its wild progenitor teosinte (Zea mays ssp. parviglumis), the mechanisms under...

  12. Maize Seed Chitinase is Modified by a Protein Secreted by Bipolaris zeicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants contain defense mechanisms that prevent infection by most fungi. Some specialized fungi have the ability to overcome plant defenses. The Zea mays (maize) seed chitinase ChitA has been previously reported as an antifungal protein. Here we report that ChitA is converted to a modified form by...

  13. DISTRIBUTION OF THE GLUTAMINE SYNTHETASE ISOZYME GSP1 IN MAIZE (ZEA MAYS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Higher plants contain families of glutamine synthetase (GS) isozymes. In maize (Zea mays L.), GSp1, the predominant GS isozyme of the developing kernel, is abundant in the pedicel and pericarp, but absent from the endosperm and embryo. Determination of GSp1 tissue distribution in vegetative tissue...

  14. Root morphology and gene expression analysis in response to drought stress in maize (Zea mays)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-deficit stress tolerance is a complex trait, and water deficit results in various physiological and chemical changes in maize (Zea mays L.) and exacerbates preharvest aflatoxin contamination. The objective of this study was to characterize the variations in morphology, physiology and gene expr...

  15. Impact of genetic structures on haploid genome-based quantification of genetically modified DNA: theoretical considerations, experimental data in MON 810 maize kernels (Zea mays L.) and some practical applications.

    PubMed

    Zhang, David; Corlet, Aurélie; Fouilloux, Stephane

    2008-06-01

    Real-time Polymerase Chain Reaction (PCR) based assays are widely used to estimate the content of genetically modified (GM) materials in food, feed and seed. It has been known that the genetic structures of the analyte can significantly influence the GM content expressed by the haploid genome (HG) % estimated using real-time PCR assays; this kind of influence is also understood as the impact of biological factors. The influence was first simulated at theoretical level using maize as a model. We then experimentally assessed the impact of biological factors on quantitative results, analysing by quantitative real-time PCR six maize MON 810 hybrid kernels with different genetic structures: (1) hemizygous from transgenic male parent, (2) hemizygous from transgenic female parent and (3) homozygous at the transgenic locus. The results obtained in the present study showed clear influences of biological factors on GM DNA quantification: 1% of GM materials by weight (wt) for the three genetic structures contained 0.39, 0.55 and 1.0% of GM DNA by HG respectively, from quantitative real-time PCR analyses. The relationships between GM wt% and GM HG% can be empirically established as: (1) in the case of the presence of a single GM trait: GM HG% = GM wt% x (0.5 +/- 0.167Y), where Y is the endosperm DNA content (%) in the total DNA of a maize kernel, (2) in the case of the presence of multiple GM traits: GM HG% = N x GM wt% x (0.5 +/- 0.167Y), where N is the number of GM traits (stacked or not) present in an unknown sample. This finding can be used by stakeholders related to GMO for empirical prediction from one unit of expression to another in the monitoring of seed and grain production chains. Practical equations have also been suggested for haploid copy number calculations, using hemizygous GM materials for calibration curves. PMID:17638110

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

    PubMed Central

    Gallavotti, Andrea; Whipple, Clinton J.

    2015-01-01

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

  17. Morphological and physiological responses of maize (Zea mays) exposed to sand contaminated by phenanthrene.

    PubMed

    Dupuy, Joan; Ouvrard, Stéphanie; Leglize, Pierre; Sterckeman, Thibault

    2015-04-01

    Phytoremediation is promising, but depends on clearly understanding contaminants' impact on plant functioning. We therefore focused on the impact of polycyclic aromatic hydrocarbons (PAH) on cultivated plants and understanding the impact of phenanthrene (PHE) on maize functioning (Zea mays). Cultivation was conducted under controlled conditions on artificially contaminated sand with PHE levels increasing from 50 to 750 mg PHE kg(-1). After four weeks, plants exposed to levels above 50 mg PHE kg(-1) presented decreased biomasses and reduced photosynthetic activity. These modifications were associated with higher biomass allocations to roots and lower ones to stems. The leaf biomass proportion was similar, with thinner blades than controls. PHE-exposed plant showed modified root architecture, with fewer roots of 0.2 and 0.4 mm in diameter. Leaves were potassium-deplete, but calcium, phosphorus, magnesium and zinc-enriched. Their content in nitrogen, iron, sulfur and manganese was unaffected. These responses resembled those of water-stress, although water contents in plant organs were not affected by PHE and water supply was not limited. They also indicated a possible perturbation of both nutritional functioning and photosynthesis. PMID:25496734

  18. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed p...

  19. Many maize inbreds lack an endosperm cytosolic phosphoglucomutase. [Zea mays L

    SciTech Connect

    Pan, D.; Stelow, L.I.; Nelson, O.E. )

    1990-08-01

    Starch gel electrophoresis of extracts from developing maize (Zea mays L.) endosperms 22 days postpollination reveals only a single zone of phosphoglucomutase activity in the majority of the inbreds tested. The other inbreds had the expected two zones of activity. The activity that is present in all inbreds is the amyloplast isozyme while the absent form is a cytosolic enzyme. The lack of the cytosolic isozyme has no discernible phenotypic consequences.

  20. 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. PMID:24243211

  1. Directly dated starch residues document early formative maize (Zea mays L.) in tropical Ecuador.

    PubMed

    Zarrillo, Sonia; Pearsall, Deborah M; Raymond, J Scott; Tisdale, Mary Ann; Quon, Dugane J

    2008-04-01

    The study of maize (Zea mays L.) domestication has advanced from questions of its origins to the study-and debate-of its dietary role and the timing of its dispersal from Mexico. Because the investigation of maize's spread is hampered by poor preservation of macrobotanical remains in the Neotropics, research has focused on microbotanical remains whose contexts are often dated by association, leading some to question the dates assigned. Furthermore, some scholars have argued that maize was not introduced to southwestern Ecuador until approximately 4150-3850 calendar years before the present (cal B.P.), that it was used first and foremost as a fermented beverage in ceremonial contexts, and that it was not important in everyday subsistence, challenging previous studies based on maize starch and phytoliths. To further investigate these questions, we analyzed every-day cooking vessels, food-processing implements, and sediments for starch and phytoliths from an archaeological site in southwestern Ecuador constituting a small Early Formative village. Employing a new technique to recover starch granules from charred cooking-pot residues we show that maize was present, cultivated, and consumed here in domestic contexts by at least 5300-4950 cal B.P. Directly dating the residues by accelerator mass spectrometry (AMS) radiocarbon measurement, our results represent the earliest direct dates for maize in Early Formative Ecuadorian sites and provide further support that, once domesticated approximately 9000 calendar years ago, maize spread rapidly from southwestern Mexico to northwestern South America. PMID:18362336

  2. Water transfer in an alfalfa/maize association. [Medicago sativa; Zea mays

    SciTech Connect

    Corak, S.J.; Blevins, D.G.; Pallardy, S.G.

    1987-07-01

    The authors investigated the possibility of interspecific water transfer in an alfalfa (Medicago sativa L.) and maize (Zea mays L.) association. An alfalfa plant was grown through two vertically stacked plastic tubes. A 5 centimeter air gap between tubes was bridged by alfalfa roots. Five-week old maize plants with roots confined to the top tube were not watered, while associated alfalfa roots had free access to water in the bottom tube (the -/+ treatment). Additional treatments included: top and bottom tubes watered (+/+), top and bottom tubes droughted (-/-), and top tube droughted after removal of alfalfa root bridges and routine removal of alfalfa tillers (-*). Predawn leaf water potential of maize in the -/+ treatment fell to -1.5 megapascals 13 days after the start of drought; thereafter, predawn and midday potentials were maintained near -1.9 megapascals. Leaf water potentials of maize in the -/- and -* treatments declined steadily; all plants in these treatments were completely desiccated before day 50. High levels of tritium activity were detected in water extracted from both alfalfa and maize leaves after /sup 3/H/sub 2/O was injected into the bottom -/+ tube at day 70 or later. Maize in the -/+ treatment was able to survive an otherwise lethal period of drought by utilizing water lost by alfalfa roots.

  3. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing.

    PubMed

    Correa-Galeote, David; Bedmar, Eulogio J; Fernández-González, Antonio J; Fernández-López, Manuel; Arone, Gregorio J

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  4. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing

    PubMed Central

    Correa-Galeote, David; Bedmar, Eulogio J.; Fernández-González, Antonio J.; Fernández-López, Manuel; Arone, Gregorio J.

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  5. Quantitative trait loci for mercury accumulation in maize (Zea mays L.) identified using a RIL population.

    PubMed

    Fu, Zhongjun; Li, Weihua; Zhang, Qinbin; Wang, Long; Zhang, Xiaoxiang; Song, Guiliang; Fu, Zhiyuan; Ding, Dong; Liu, Zonghua; Tang, Jihua

    2014-01-01

    To investigate the genetic mechanism of mercury accumulation in maize (Zea mays L.), a population of 194 recombinant inbred lines derived from an elite hybrid Yuyu 22, was used to identify quantitative trait loci (QTLs) for mercury accumulation at two locations. The results showed that the average Hg concentration in the different tissues of maize followed the order: leaves > bracts > stems > axis > kernels. Twenty-three QTLs for mercury accumulation in five tissues were detected on chromosomes 1, 4, 7, 8, 9 and 10, which explained 6.44% to 26.60% of the phenotype variance. The QTLs included five QTLs for Hg concentration in kernels, three QTLs for Hg concentration in the axis, six QTLs for Hg concentration in stems, four QTLs for Hg concentration in bracts and five QTLs for Hg concentration in leaves. Interestingly, three QTLs, qKHC9a, qKHC9b, and qBHC9 were in linkage with two QTLs for drought tolerance. In addition, qLHC1 was in linkage with two QTLs for arsenic accumulation. The study demonstrated the concentration of Hg in Hg-contaminated paddy soil could be reduced, and maize production maintained simultaneously by selecting and breeding maize Hg pollution-safe cultivars (PSCs). PMID:25210737

  6. Quantitative Trait Loci for Mercury Accumulation in Maize (Zea mays L.) Identified Using a RIL Population

    PubMed Central

    Zhang, Qinbin; Wang, Long; Zhang, Xiaoxiang; Song, Guiliang; Fu, Zhiyuan; Ding, Dong; Liu, Zonghua; Tang, Jihua

    2014-01-01

    To investigate the genetic mechanism of mercury accumulation in maize (Zea mays L.), a population of 194 recombinant inbred lines derived from an elite hybrid Yuyu 22, was used to identify quantitative trait loci (QTLs) for mercury accumulation at two locations. The results showed that the average Hg concentration in the different tissues of maize followed the order: leaves > bracts > stems > axis > kernels. Twenty-three QTLs for mercury accumulation in five tissues were detected on chromosomes 1, 4, 7, 8, 9 and 10, which explained 6.44% to 26.60% of the phenotype variance. The QTLs included five QTLs for Hg concentration in kernels, three QTLs for Hg concentration in the axis, six QTLs for Hg concentration in stems, four QTLs for Hg concentration in bracts and five QTLs for Hg concentration in leaves. Interestingly, three QTLs, qKHC9a, qKHC9b, and qBHC9 were in linkage with two QTLs for drought tolerance. In addition, qLHC1 was in linkage with two QTLs for arsenic accumulation. The study demonstrated the concentration of Hg in Hg-contaminated paddy soil could be reduced, and maize production maintained simultaneously by selecting and breeding maize Hg pollution-safe cultivars (PSCs). PMID:25210737

  7. Effect of biochar on reclaimed tidal land soil properties and maize (Zea mays L.) response.

    PubMed

    Kim, Hyuck-Soo; Kim, Kwon-Rae; Yang, Jae E; Ok, Yong Sik; Owens, Gary; Nehls, Thomas; Wessolek, Gerd; Kim, Kye-Hoon

    2016-01-01

    Reclaimed tidal land soil (RTLS) often contains high levels of soluble salts and exchangeable Na that can adversely affect plant growth. The current study examined the effect of biochar on the physicochemical properties of RTLS and subsequently the influence on plant growth performance. Rice hull derived biochar (BC) was applied to RTLS at three different rates (1%, 2%, and 5% (w/w)) and maize (Zea mays L.) subsequently cultivated for 6weeks. While maize was cultivated, 0.1% NaCl solution was supplied from the bottom of the pots to simulate the natural RTLS conditions. Biochar induced changes in soil properties were evaluated by the water stable aggregate (WSA) percentage, exchangeable sodium percentage (ESP), soil organic carbon contents, cation exchange capacity, and exchangeable cations. Plant response was measured by growth rate, nutrient contents, and antioxidant enzyme activity of ascorbate peroxidase (APX) and glutathione reductase (GR). Application of rice hull derived biochar increased the soil organic carbon content and the percentage of WSA by 36-69%, while decreasing the ESP. The highest dry weight maize yield was observed from soil which received 5% BC (w/w), which was attributed to increased stability of water-stable aggregates and elevated levels of phosphate in BC incorporated soils. Moreover, increased potassium, sourced from the BC, induced mitigation of Na uptake by maize and consequently, reduced the impact of salt stress as evidenced by overall declines in the antioxidant activities of APX and GR. PMID:26138709

  8. Study of effects of Bt maize (Zea mays) events on Lepidoptera Ostrinia nubilalis, Sesamia nonagrioidesin southwestern France.

    PubMed

    Folcher, L; Eychenne, N; Weissenberger, A; Jarry, M; Regnault-Roger, C; Delos, M

    2006-01-01

    Crops of maize (Zea mays L.) were conducted in southwestern France with GMO (Genetic Modified Organism) vs isogenetic varieties in order to verify the control of European Corn Borer (ECB) Ostrinia nubilalis (Hübner) and the Corn Stalk Borer (CBS) Sesamia nonagrioides (Lefevbre) by GMO in field conditions. The bioassays were carried out in 1998 and 1999 before moratorium, then in 2005. Experiments involved respectively 18, 12 and 19 fields cultivated with Furio/Furio cb (GMO), Cecilia/ Elgina (GMO) and PR33P66/PR33P67 (GMO) varieties. These transgenic events expressed Cry1A(b) protein (Bt maize). Plants were noted for insect infestation assessment (number of larvae in stalks and ears per plant). Statistical tests used t-test on couple of plots. Results showed a significant difference in the density of both ECB and CBS between control and the two transgenic events. The two transgenic events acted differently. The control of the two Bt events on the two pests were differentiated and discussed. These experiments underlined the importance of field evaluation for testing real effects of transgenic events on crop according the environmental context. PMID:17390797

  9. Gibberella Ear Rot of Maize (Zea mays) in Nepal: Distribution of the Mycotoxins Nivalenol and Deoxynivalenol in Naturally and Experimentally Infected Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Fusarium graminearum (sexual stage Gibberella zeae) causes ear rot of maize (Zea mays) and contamination with the 8-ketotrichothecenes nivalenol (NIV) or 4-deoxynivalenol (DON), depending on diversity of the fungal population for the 4-oxygenase gene (TRI13). To determine the importance ...

  10. Quantitative Trait Loci for Maysin Synthesis in Maize (Zea mays L.) Lines Selected for High Silk Maysin Content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recurrent selection has been utilized for over a century to increase desired traits in crop plants. One notable trait of interest to plant breeders is insect resistance. Maysin is a naturally occurring C-glycosyl flavone found in maize (Zea mays L.) silk tissue that confers resistance to corn earwor...

  11. Occultifur kilbournensis f.a. sp. nov., a new member of the Cystobasidiales associated with maize (Zea mays) cultivation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a study of microorganisms associated with maize (Zea mays) cultivation, yeasts were isolated from overwintered stalks, cobs and surrounding soil, which were collected from an agricultural field in south-central Illinois, USA. Predominant among isolates were two species of Cryptococcus (Cr. fl...

  12. The effect and fate of water-soluble carbon nanodots in maize (Zea mays L.).

    PubMed

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

    2016-08-01

    In this study, the toxicity of water-soluble carbon nanodots (C-dots) to maize (Zea mays L.) and their uptake and transport in plants were investigated. After exposed in sand matrix amended with 0-2000 mg/L C-dots for 4 weeks, we found that the phytotoxicity of C-dots was concentration-dependent. C-dots at 250 and 500 mg/L showed no toxicity to maize. However, 1000 and 2000 mg/L C-dots significantly reduced the fresh weight of root by 57% and 68%, and decreased the shoot fresh weight by 38% and 72%, respectively. Moreover, in maize roots, the exposure of C-dots at 2000 mg/L significantly increased the H2O2 content and lipid peroxidation (6.5 and 1.65 times higher, respectively), as well as, the antioxidant enzymes activities, up to 2, 1.5, 1.9 and 1.9 times higher for catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase, respectively. On the other hand, C-dots were observed in detached root-cap cells, cortex and vascular bundle of roots and mesophyll cells of leaves through fluorescence microscopy analysis, suggesting that C-dots were absorbed and translocated systemically in maize. Remarkably, a certain amount of C-dots were excreted out from leaf blade. To our knowledge, this is the first study combined phenotypic observation with physiologic responses and bioaccumulation and translocation analysis of C-dots to investigate their effect and fate in maize. PMID:26694806

  13. Response of maize (Zea mays L. saccharata Sturt) to different concentration treatments of deltamethrin.

    PubMed

    Duran, Ragbet Ezgi; Kilic, Semra; Coskun, Yasemin

    2015-10-01

    The aim of this study was to investigate the effect of the deltamethrin pesticide on the biological properties of maize (Zea mays L. saccharata Sturt). Maize seeds were exposed to environmentally relevant dosages (0.01, 0.05, 0.1 and 0.5 ppm) of deltamethrin. On the 7th day of germination, morphological, anatomical and physiological responses were determined. All seedling growth characters were decreased with increasing deltamethrin levels. The most negative effect on the radicle length of maize was observed by the highest deltamethrin concentration with a 61% decrease (P <0.05). Both stomatal density and stomatal dimension reduction were caused by increasing concentrations of deltamethrin. Moreover, the pigments like chlorophyll a, chlorophyll b, total chlorophyll and caretonoids decreased with the increase in deltamethrin concentration. Conversely, anthocyanin and proline content increased in parallel with deltamethrin concentration. As a result, all morphological traits and pigments except for proline and anthocyanin were significantly reduced with an increase in pesticide concentration, compared to control (P <0.05). PMID:26453225

  14. [Evaluation of a methodology to determine texture characteristics of maize (Zea mays L.) tortilla].

    PubMed

    Arámbula-Villa, Gerónimo; Méndez-Albores, J Abraham; González-Hernández, Jesús; Gutiérrez-Arias, Edmundo; Moreno-Martínez, Ernesto

    2004-06-01

    Maize (Zea mays L.) tortilla is the primary staple food of the Mexican people, with annual consumption estimated at 12 millions tons. Despite this huge volume of consumption, tortillas are commercially produced with inconsistent quality, mainly in terms of texture characteristics. Different methods to evaluate the texture of maize tortillas have been reported, but the values obtained and their parameters have not yielded reliable results, largely because the methods used do not reflect homogeneous elements for comparison. In addition, evaluation of the reliability of methods for comparing tortilla texture as well as the equipment used has been difficult, as such information perhaps remains largely unpublished. In this study, the reliability of two tortilla sample shapes (rectangle and briquet) and some of the quality parameters (maximum force, total area under curve, area to reach maximum force, elasticity and elongation) from tensile and cut force tested with a texture meter were evaluated. According to the results, the briquet shape of the tortilla samples was better (than the rectangle shape) for determining tensile and elasticity. In regard to cutting force, both the rectangle and the briquet shape presented good repeatability. For tensile and cutting-force curves, the maximum force was the parameter with the highest reliability, 0.95 and 0.99, respectively. The elasticity showed an adequate reliability with the tortilla briquet shape (0.94). The evaluated parameters with the texture meter and the sample shape type briquet, showed a high reliability degree what makes possible the comparison of maize tortilla texture data. PMID:15586691

  15. Patterns of diversity and recombination along chromosome 1 of maize (Zea mays ssp. mays L.).

    PubMed Central

    Tenaillon, Maud I; Sawkins, Mark C; Anderson, Lorinda K; Stack, Stephen M; Doebley, John; Gaut, Brandon S

    2002-01-01

    We investigate the interplay between genetic diversity and recombination in maize (Zea mays ssp. mays). Genetic diversity was measured in three types of markers: single-nucleotide polymorphisms, indels, and microsatellites. All three were examined in a sample of previously published DNA sequences from 21 loci on maize chromosome 1. Small indels (1-5 bp) were numerous and far more common than large indels. Furthermore, large indels (>100 bp) were infrequent in the population sample, suggesting they are slightly deleterious. The 21 loci also contained 47 microsatellites, of which 33 were polymorphic. Diversity in SNPs, indels, and microsatellites was compared to two measures of recombination: C (=4Nc) estimated from DNA sequence data and R based on a quantitative recombination nodule map of maize synaptonemal complex 1. SNP diversity was correlated with C (r = 0.65; P = 0.007) but not with R (r = -0.10; P = 0.69). Given the lack of correlation between R and SNP diversity, the correlation between SNP diversity and C may be driven by demography. In contrast to SNP diversity, microsatellite diversity was correlated with R (r = 0.45; P = 0.004) but not C (r = -0.025; P = 0.55). The correlation could arise if recombination is mutagenic for microsatellites, or it may be consistent with background selection that is apparent only in this class of rapidly evolving markers. PMID:12454083

  16. Phosphorylation of ribosomal proteins induced by auxins in maize embryonic tissues. [Zea mays

    SciTech Connect

    Perez, L.; Aguilar, R.; Mendez, A.P.; de Jimenez, E.S.

    1990-11-01

    The effect of auxin on ribosomal protein phosphorylation of germinating maize (Zea mays) tissues was investigated. Two-dimensional gel electrophoresis and autoradiography of ({sup 32}P) ribosomal protein patterns for natural and synthetic auxin-treated tissues were performed. Both the rate of {sup 32}P incorporation and the electrophoretic patterns were dependent on {sup 32}P pulse length, suggesting that active protein phosphorylation-dephosphorylation occurred in small and large subunit proteins, in control as well as in auxin-treated tissues. The effect of ribosomal protein phosphorylation on in vitro translation was tested. Measurements of poly(U) translation rates as a function of ribosome concentration provided apparent K{sub m} values significantly different for auxin-treated and nontreated tissues. These findings suggest that auxin might exert some kind of translational control by regulating the phosphorylated status of ribosomal proteins.

  17. Differentiation of the properties of the branching isozymes from maize (Zea mays)

    SciTech Connect

    Guan, H.P.; Preiss, J. )

    1993-08-01

    The multiple forms of branching enzyme (BE) from developing maize (Zea mays) endosperm were purified by modification of previous procedures such that amylase activity could be eliminated completely from the BE preparation. Three distinct assays for BE activity (phosphorylase a stimulation assay, BE linkage assay, and iodine stain assay) were used to characterize and differentiate that properties of the BE isoforms. This study present s the first evidence that the BE isoforms differ in their action on amylopectin. BEI has the highest activity in branching amylose, but its rate of branching amylopectin was less than 5% of that of branching amylose. Conversely, BEII isoforms had lower rates in branching amylose (about 9--12% of that of BEI) and had higher rates of branching amylopectin (about 6-fold) than BEI. The implication of these findings to the mechanism of amylopectin synthesis in vivo are discussed. 21 refs., 1 figs., 5 tabs.

  18. Cloning and Functional Characterization of the Maize (Zea mays L.) Carotenoid Epsilon Hydroxylase Gene

    PubMed Central

    Sheng, Yanmin; Wang, Yingdian; Capell, Teresa; Shi, Lianxuan; Ni, Xiuzhen; Sandmann, Gerhard; Christou, Paul; Zhu, Changfu

    2015-01-01

    The assignment of functions to genes in the carotenoid biosynthesis pathway is necessary to understand how the pathway is regulated and to obtain the basic information required for metabolic engineering. Few carotenoid ε-hydroxylases have been functionally characterized in plants although this would provide insight into the hydroxylation steps in the pathway. We therefore isolated mRNA from the endosperm of maize (Zea mays L., inbred line B73) and cloned a full-length cDNA encoding CYP97C19, a putative heme-containing carotenoid ε hydroxylase and member of the cytochrome P450 family. The corresponding CYP97C19 genomic locus on chromosome 1 was found to comprise a single-copy gene with nine introns. We expressed CYP97C19 cDNA under the control of the constitutive CaMV 35S promoter in the Arabidopsis thaliana lut1 knockout mutant, which lacks a functional CYP97C1 (LUT1) gene. The analysis of carotenoid levels and composition showed that lutein accumulated to high levels in the rosette leaves of the transgenic lines but not in the untransformed lut1 mutants. These results allowed the unambiguous functional annotation of maize CYP97C19 as an enzyme with strong zeinoxanthin ε-ring hydroxylation activity. PMID:26030746

  19. Proteome Changes in Maize Embryo (Zea mays L) Induced by Ion Beam Implantation Treatment

    NASA Astrophysics Data System (ADS)

    Li, Yongliang; Tang, Jihua; Qin, Guangyong; Huo, Yuping; Tian, Shuangqi

    2009-08-01

    Low energy ion beam implantation was applied to the maize (Zea mays L) embryo proteome using two-dimensional gel electrophoresis. Protein profile analysis detected more than 1100 protein spots, 72 of which were determined to be expressed differently in the treated and control (not exposed to ion beam implantation) embryos. Of the 72 protein spots, 53 were up-regulated in the control and 19 were more abundantly expressed in the ion beam-treated embryos. The spots of up- or down-regulated proteins were identified by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Among the identified proteins, 11 were up-regulated in the treated embryos. Four of these up-regulated proteins were antioxidant molecules, three were related to stress response, two to sugar metabolism and two were associated with heat shock response. Of the five proteins up-regulated in the control embryos, three were functionally related to carbohydrate metabolism; the functions of the remaining two proteins were unknown. The data collected during this study indicate that treatment of maize embryos with low energy ion beam implantation induces changes in stress tolerance enzymes/proteins, possibly as a result of alterations in metabolism.

  20. Patterns of DNA sequence polymorphism along chromosome 1 of maize (Zea mays ssp. mays L.)

    PubMed Central

    Tenaillon, Maud I.; Sawkins, Mark C.; Long, Anthony D.; Gaut, Rebecca L.; Doebley, John F.; Gaut, Brandon S.

    2001-01-01

    We measured sequence diversity in 21 loci distributed along chromosome 1 of maize (Zea mays ssp. mays L.). For each locus, we sequenced a common sample of 25 individuals representing 16 exotic landraces and nine U.S. inbred lines. The data indicated that maize has an average of one single nucleotide polymorphism (SNP) every 104 bp between two randomly sampled sequences, a level of diversity higher than that of either humans or Drosophila melanogaster. A comparison of genetic diversity between the landrace and inbred samples showed that inbreds retained 77% of the level of diversity of landraces, on average. In addition, Tajima's D values suggest that the frequency distribution of polymorphisms in inbreds was skewed toward fewer rare variants. Tests for selection were applied to all loci, and deviations from neutrality were detected in three loci. Sequence diversity was heterogeneous among loci, but there was no pattern of diversity along the genetic map of chromosome 1. Nonetheless, diversity was correlated (r = 0.65) with sequence-based estimates of the recombination rate. Recombination in our sample was sufficient to break down linkage disequilibrium among SNPs. Intragenic linkage disequilibrium declines within 100–200 bp on average, suggesting that genome-wide surveys for association analyses require SNPs every 100–200 bp. PMID:11470895

  1. Low Water Potential Disrupts Carbohydrate Metabolism in Maize (Zea mays L.) Ovaries.

    PubMed Central

    Zinselmeier, C.; Westgate, M. E.; Schussler, J. R.; Jones, R. J.

    1995-01-01

    Water deficit during pollination increases the frequency of kernel abortion in maize (Zea mays L.). Much of the kernel loss is attributable to lack of current photosynthate, but a large number of kernels fail to develop on water-deficient plants even when assimilate supply is increased. We examined the possibility that assimilate utilization by developing ovaries might be impaired at low water potential ([Psi]w). Plants were grown in the greenhouse in 20-L pots containing 22 kg of amended soil. Water was withheld on the first day silks emerged, and plants were hand-pollinated 4 d later when leaf [Psi]w decreased to approximately - 1.8 MPa and silk [Psi]w was approximately -1.0 MPa. Plants were rehydrated 2 d after pollination. The brief water deficit inhibited ovary growth (dry matter accumulation) and decreased kernel number per ear by 60%, compared to controls. Inhibition of ovary growth was associated with a decrease in the level of reducing sugars, depletion of starch, a 75-fold increase in sucrose concentration (dry weight basis), and inhibition of acid invertase (EC 3.2.1.26) activity. These results indicate that water deficits during pollination disrupt carbohydrate metabolism in maize ovaries. They suggest that acid invertase activity is important for establishing and maintaining reproductive sink strength during pollination and early kernel development. PMID:12228365

  2. Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

    PubMed Central

    Szpak, Paul; Longstaffe, Fred J.; Millaire, Jean-François; White, Christine D.

    2012-01-01

    Background Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ15N). Animal excrement is known to impact plant δ15N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint. Methodology/Principal Findings This paper presents isotopic (δ13C and δ15N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of 15N enrichment in fertilized plants is very large, with δ15N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ15N values ranged between −0.3 and 5.7‰. Intraplant and temporal variability in δ15N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ13C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk. Conclusions/Significance The results presented in this study demonstrate the very large impact of seabird guano on maize δ15N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must

  3. Global gene expression analysis of the shoot apical meristem of maize (Zea mays L.)

    PubMed Central

    Ohtsu, Kazuhiro; Smith, Marianne B; Emrich, Scott J; Borsuk, Lisa A; Zhou, Ruilian; Chen, Tianle; Zhang, Xiaolan; Timmermans, Marja C P; Beck, Jon; Buckner, Brent; Janick-Buckner, Diane; Nettleton, Dan; Scanlon, Michael J; Schnable, Patrick S

    2007-01-01

    All above-ground plant organs are derived from shoot apical meristems (SAMs). Global analyses of gene expression were conducted on maize (Zea mays L.) SAMs to identify genes preferentially expressed in the SAM. The SAMs were collected from 14-day-old B73 seedlings via laser capture microdissection (LCM). The RNA samples extracted from LCM-collected SAMs and from seedlings were hybridized to microarrays spotted with 37 660 maize cDNAs. Approximately 30% (10 816) of these cDNAs were prepared as part of this study from manually dissected B73 maize apices. Over 5000 expressed sequence tags (ESTs) (about 13% of the total) were differentially expressed (P<0.0001) between SAMs and seedlings. Of these, 2783 and 2248 ESTs were up- and down-regulated in the SAM, respectively. The expression in the SAM of several of the differentially expressed ESTs was validated via quantitative RT-PCR and/or in situ hybridization. The up-regulated ESTs included many regulatory genes including transcription factors, chromatin remodeling factors and components of the gene-silencing machinery, as well as about 900 genes with unknown functions. Surprisingly, transcripts that hybridized to 62 retrotransposon-related cDNAs were also substantially up-regulated in the SAM. Complementary DNAs derived from the LCM-collected SAMs were sequenced to identify additional genes that are expressed in the SAM. This generated around 550 000 ESTs (454-SAM ESTs) from two genotypes. Consistent with the microarray results, approximately 14% of the 454-SAM ESTs from B73 were retrotransposon-related. Possible roles of genes that are preferentially expressed in the SAM are discussed. PMID:17764504

  4. Usefulness of Multiparental Populations of Maize (Zea mays L.) for Genome-Based Prediction

    PubMed Central

    Lehermeier, Christina; Krämer, Nicole; Bauer, Eva; Bauland, Cyril; Camisan, Christian; Campo, Laura; Flament, Pascal; Melchinger, Albrecht E.; Menz, Monica; Meyer, Nina; Moreau, Laurence; Moreno-González, Jesús; Ouzunova, Milena; Pausch, Hubert; Ranc, Nicolas; Schipprack, Wolfgang; Schönleben, Manfred; Walter, Hildrun; Charcosset, Alain; Schön, Chris-Carolin

    2014-01-01

    The efficiency of marker-assisted prediction of phenotypes has been studied intensively for different types of plant breeding populations. However, one remaining question is how to incorporate and counterbalance information from biparental and multiparental populations into model training for genome-wide prediction. To address this question, we evaluated testcross performance of 1652 doubled-haploid maize (Zea mays L.) lines that were genotyped with 56,110 single nucleotide polymorphism markers and phenotyped for five agronomic traits in four to six European environments. The lines are arranged in two diverse half-sib panels representing two major European heterotic germplasm pools. The data set contains 10 related biparental dent families and 11 related biparental flint families generated from crosses of maize lines important for European maize breeding. With this new data set we analyzed genome-based best linear unbiased prediction in different validation schemes and compositions of estimation and test sets. Further, we theoretically and empirically investigated marker linkage phases across multiparental populations. In general, predictive abilities similar to or higher than those within biparental families could be achieved by combining several half-sib families in the estimation set. For the majority of families, 375 half-sib lines in the estimation set were sufficient to reach the same predictive performance of biomass yield as an estimation set of 50 full-sib lines. In contrast, prediction across heterotic pools was not possible for most cases. Our findings are important for experimental design in genome-based prediction as they provide guidelines for the genetic structure and required sample size of data sets used for model training. PMID:25236445

  5. Antioxidant, α-glucosidase and xanthine oxidase inhibitory activity of bioactive compounds from maize (Zea mays L.).

    PubMed

    Nile, Shivraj H; Park, Se W

    2014-01-01

    Chemical investigations into maize (Zea mays L.) kernels yielded phenolic compounds, which were structurally established using chromatographic and spectroscopic methods. The isolated phenolic compounds from maize kernel were examined in vitro for their antioxidant abilities by DPPH (2,2-diphenyl-1-picryl hydrazine) radical, OH radical scavenging activity, and reducing ability, along with α-glucosidase and xanthine oxidase (XO) inhibition. The isolated maize phenolics revealed significant xanthine oxidase and α-glucosidase inhibitory activity to that of allopurinol and acarbose in vitro and in vivo, respectively. The kinetics study with xanthine oxidase revealed competitive type of inhibition by isolated maize vanillic acid (M2), ferulic acid (M5), 3'-methoxyhirsutrin (M7), and peonidin-3-glucoside (M10) as compared to control allopurinol. Overall, with few exceptions, all the phenolic compounds from maize kernel revealed significant biological activities with all parameters examined. Also, the phenolic compounds from maize were found to be more reactive toward DPPH radical and had considerable reducing ability and OH radical scavenging activity. These findings suggest that maize kernel phenolic compounds can be considered as potential antioxidant, α-glucosidase, and XO inhibitory agents those might be further explored for the design of lead antioxidant, antidiabetic and antigout drug candidates using in vivo trials. PMID:23957301

  6. Maize (Zea mays L.) performance in organically amended mine site soils.

    PubMed

    Oladipo, Oluwatosin Gbemisola; Olayinka, Akinyemi; Awotoye, Olusegun Olufemi

    2016-10-01

    Organic amendments play an important role in the eco-friendly remediation of degraded mine site soils. This study investigated the quality (essential nutrients and heavy metal content) of maize grown on organically amended soils from three active mines in Nigeria. Soil samples were collected randomly at 0-15 cm depth, air-dried and sieved. Five kg of soil were amended with poultry manure and sawdust (poultry manure only, sawdust only, poultry manure-sawdust mixtures in 3:1, 2:1 and 1:1 ratios) at 10 g kg(-1). Maize (Zea mays L.) seeds were planted and watered for two consecutive periods of 8 weeks, with the control and treatment experiments set up in the screenhouse in quadruples. Harvested tissues were weighed, dried, ground and digested. Chemical properties were determined using standard methods while atomic absorption spectrophotometry was used to determine total metal concentrations (Ca, Mg, Fe, Zn, Pb, Cd and Cu). ANOVA was used to test for significant differences among treatment groups in the various parameters. Application of poultry manure-sawdust mixtures significantly (p < 0.05) enhanced tissue dry matter yield, as well as N, P, K, and Na contents while Zn, Cd, Cu and Pb were immobilized to approximately 50-100%. Treatment with sawdust alone reduced tissue nutrient content resulting in depressed plant yield while poultry manure only though enhanced crop yield, contained higher heavy metal contents. Soil amendments comprised of poultry manure-sawdust mixtures can be effective remediation strategy for mine site soils, as these organic materials help replenish soil nutrients, immobilize heavy metals, and enhance food productivity. PMID:27415409

  7. Net irrigation requirements for maize (Zea mays L.) in Bocono-Masparro interfluvium area.

    NASA Astrophysics Data System (ADS)

    Farias Ramirez, Asdrubal Jesus; Moreno Pizani, Maria Alejandra

    2013-04-01

    Irrigated agriculture is one of the largest consumers of fresh water. In situations where water resources are limited, the irrigation for crops has led to water use conflicts because of human, hydroelectric and industrial demands. Thus, achieving precise information about water availability and water needs of crops becomes safety factors to guarantee sustainable development of irrigated crops in the future. In Bocono-Masparro interfluvium area located within Barinas and Portuguesa states in Venezuela, there has been a significant increase in intensive farming with maize (Zea mays L.) which made essential to determine the availability of irrigation water to meet the crop requirement and improve the management based on planning designs. Due to the lack of irrigation requirements data for the study area, a methodology was developed to estimate the net irrigation requirements (NIR). Therefore, the available information of this region related to climate, soil and irrigation was used to estimate NIR for maize through CROPWAT 8.0 model. There were established different crop-climate-soil combinations that allowed estimating NIR. It was found that NIR did not exceed the value of 125 mm/month in all of the combinations. Based on these results, a NIR spatial distribution map was obtained through the use of ArcView 3.2 ®. The results showed that the highest NIR were located in the northeast sector of the study area which was associated to the influence of the Weather Station named San Hipolito. Additionally, the estimated availability of groundwater was found to be higher than the surface water, and both combined exceeded the demands of the study area. The model CROPWAT 8.0 provided necessary information for irrigation planning in large scale. A NIR map developed through the proposed methodology represents a useful tool to integrate water balance factors.

  8. Comparative Proteomic Analysis of the Response of Maize (Zea mays L.) Leaves to Long Photoperiod Condition.

    PubMed

    Wu, Liuji; Tian, Lei; Wang, Shunxi; Zhang, Jun; Liu, Ping; Tian, Zhiqiang; Zhang, Huimin; Liu, Haiping; Chen, Yanhui

    2016-01-01

    Maize (Zea mays L.), an important industrial material and food source, shows an astonishing environmental adaptation. A remarkable feature of its post-domestication adaptation from tropical to temperate environments is adaptation to a long photoperiod (LP). Many photoperiod-related genes have been identified in previous transcriptomics analysis, but proteomics shows less evidence for this mechanism of photoperiod response. In this study, we sampled newly expanded leaves of maize at the three- and six-leaf stages from an LP-sensitive introgression line H496, the donor CML288, LP-insensitive inbred line, and recurrent parent Huangzao4 (HZ4) grown under long days (15 h light and 9 h dark). To characterize the proteomic changes in response to LP, the iTRAQ-labeling method was used to determine the proteome profiles of plants exposed to LP. A total of 943 proteins differentially expressed at the three- and six-leaf stages in HZ4 and H496 were identified. Functional analysis was performed by which the proteins were classified into stress defense, signal transduction, carbohydrate metabolism, protein metabolism, energy production, and transport functional groups using the WEGO online tool. The enriched gene ontology categories among the identified proteins were identified statistically with the Cytoscape plugin ClueGO + Cluepedia. Twenty Gene Ontology terms showed the highest significance, including those associated with protein processing in the endoplasmic reticulum, splicesome, ribosome, glyoxylate, dicarboxylate metabolism, L-malate dehydrogenase activity, and RNA transport. In addition, for subcellular location, all proteins showed significant enrichment of the mitochondrial outer membrane. The sugars producted by photosynthesis in plants are also a pivotal metabolic output in the circadian regulation. The results permit the prediction of several crucial proteins to photoperiod response and provide a foundation for further study of the influence of LP treatments on

  9. Fungal-fungal associations affect the assembly of endophyte communities in maize (Zea mays).

    PubMed

    Pan, Jean J; May, Georgiana

    2009-10-01

    Many factors can affect the assembly of communities, ranging from species pools to habitat effects to interspecific interactions. In microbial communities, the predominant focus has been on the well-touted ability of microbes to disperse and the environment acting as a selective filter to determine which species are present. In this study, we investigated the role of biotic interactions (e.g., competition, facilitation) in fungal endophyte community assembly by examining endophyte species co-occurrences within communities using null models. We used recombinant inbred lines (genotypes) of maize (Zea mays) to examine community assembly at multiple habitat levels, at the individual plant and host genotype levels. Both culture-dependent and culture-independent approaches were used to assess endophyte communities. Communities were analyzed using the complete fungal operational taxonomic unit (OTU) dataset or only the dominant (most abundant) OTUs in order to ascertain whether species co-occurrences were different for dominant members compared to when all members were included. In the culture-dependent approach, we found that for both datasets, OTUs co-occurred on maize genotypes more frequently than expected under the null model of random species co-occurrences. In the culture-independent approach, we found that OTUs negatively co-occurred at the individual plant level but were not significantly different from random at the genotype level for either the dominant or complete datasets. Our results showed that interspecific interactions can affect endophyte community assembly, but the effects can be complex and depend on host habitat level. To our knowledge, this is the first study to examine endophyte community assembly in the same host species at multiple habitat levels. Understanding the processes and mechanisms that shape microbial communities will provide important insights into microbial community structure and the maintenance of microbial biodiversity. PMID:19517158

  10. β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

    PubMed

    Shaw, Arun K; Bhardwaj, Pardeep K; Ghosh, Supriya; Roy, Sankhajit; Saha, Suman; Sherpa, Ang R; Saha, Samir K; Hossain, Zahed

    2016-02-01

    The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response. PMID:26416125

  11. Comparative Proteomic Analysis of the Response of Maize (Zea mays L.) Leaves to Long Photoperiod Condition

    PubMed Central

    Wu, Liuji; Tian, Lei; Wang, Shunxi; Zhang, Jun; Liu, Ping; Tian, Zhiqiang; Zhang, Huimin; Liu, Haiping; Chen, Yanhui

    2016-01-01

    Maize (Zea mays L.), an important industrial material and food source, shows an astonishing environmental adaptation. A remarkable feature of its post-domestication adaptation from tropical to temperate environments is adaptation to a long photoperiod (LP). Many photoperiod-related genes have been identified in previous transcriptomics analysis, but proteomics shows less evidence for this mechanism of photoperiod response. In this study, we sampled newly expanded leaves of maize at the three- and six-leaf stages from an LP-sensitive introgression line H496, the donor CML288, LP-insensitive inbred line, and recurrent parent Huangzao4 (HZ4) grown under long days (15 h light and 9 h dark). To characterize the proteomic changes in response to LP, the iTRAQ-labeling method was used to determine the proteome profiles of plants exposed to LP. A total of 943 proteins differentially expressed at the three- and six-leaf stages in HZ4 and H496 were identified. Functional analysis was performed by which the proteins were classified into stress defense, signal transduction, carbohydrate metabolism, protein metabolism, energy production, and transport functional groups using the WEGO online tool. The enriched gene ontology categories among the identified proteins were identified statistically with the Cytoscape plugin ClueGO + Cluepedia. Twenty Gene Ontology terms showed the highest significance, including those associated with protein processing in the endoplasmic reticulum, splicesome, ribosome, glyoxylate, dicarboxylate metabolism, L-malate dehydrogenase activity, and RNA transport. In addition, for subcellular location, all proteins showed significant enrichment of the mitochondrial outer membrane. The sugars producted by photosynthesis in plants are also a pivotal metabolic output in the circadian regulation. The results permit the prediction of several crucial proteins to photoperiod response and provide a foundation for further study of the influence of LP treatments on

  12. Zea mI, the maize homolog of the allergen-encoding Lol pI gene of rye grass.

    PubMed

    Broadwater, A H; Rubinstein, A L; Chay, C H; Klapper, D G; Bedinger, P A

    1993-09-15

    Sequence analysis of a pollen-specific cDNA from maize has identified a homolog (Zea mI) of the gene (Lol pI) encoding the major allergen of rye-grass pollen. The protein encoded by the partial cDNA sequence is 59.3% identical and 72.7% similar to the comparable region of the reported amino acid sequence of Lol pIA. Southern analysis indicates that this cDNA represents a member of a small multigene family in maize. Northern analysis shows expression only in pollen, not in vegetative or female floral tissues. The timing of expression is developmentally regulated, occurring at a low level prior to the first pollen mitosis and at a high level after this postmeiotic division. Western analysis detects a protein in maize pollen lysates using polyclonal antiserum and monoclonal antibodies directed against purified Lolium perenne allergen. PMID:8406014

  13. Use of poultry manure for amendment of oil-polluted soils in relation to growth of maize (Zea mays L. )

    SciTech Connect

    Amadi, A. ) Ue Bari, Y. )

    1992-01-01

    The use of poultry manure for amelioration of oil-polluted soil was investigated by growing maize (Zea mays L.) under two experimental conditions: increasing the poultry manure rate from 0-20 kg ha{sup {minus}1} at 0.03 L/kg oil treatment level; and increasing the rate of oil treatment from 0-0.2 between the rate of poultry manure added and the enhancement of maize growth. But only a 16-kg ha{sup {minus}1} poultry manure rate and above exerted some beneficial effects on the maize growth relative to the unpolluted, unamended soil. Conversely, increasing oil concentration, regardless of the poultry manure level added, depressed maize growth, but only at oil levels of 0.03 L/kg. A positive correlation was recorded between maize height and leaf area growing in oil-treated soil amended with different poultry manure rates and growing in oil-treated amended with 20 kg ha{sup {minus}1} poultry manure. Amending oil-contaminated soils with poultry manure, should possibly improve soil fertility and maize production.

  14. The maize (Zea mays ssp. mays var. B73) genome encodes 33 members of the purple acid phosphatase family

    PubMed Central

    González-Muñoz, Eliécer; Avendaño-Vázquez, Aida-Odette; Montes, Ricardo A. Chávez; de Folter, Stefan; Andrés-Hernández, Liliana; Abreu-Goodger, Cei; Sawers, Ruairidh J. H.

    2015-01-01

    Purple acid phosphatases (PAPs) play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73) reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members. PMID:26042133

  15. The maize (Zea mays ssp. mays var. B73) genome encodes 33 members of the purple acid phosphatase family.

    PubMed

    González-Muñoz, Eliécer; Avendaño-Vázquez, Aida-Odette; Montes, Ricardo A Chávez; de Folter, Stefan; Andrés-Hernández, Liliana; Abreu-Goodger, Cei; Sawers, Ruairidh J H

    2015-01-01

    Purple acid phosphatases (PAPs) play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73) reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members. PMID:26042133

  16. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila.

    PubMed

    Li, T; Liu, M J; Zhang, X T; Zhang, H B; Sha, T; Zhao, Z W

    2011-02-15

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. PMID:21195456

  17. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

    PubMed

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

  18. Effects of experimental warming on stomatal traits in leaves of maize (Zea may L.)

    PubMed Central

    Zheng, Yunpu; Xu, Ming; Hou, Ruixing; Shen, Ruichang; Qiu, Shuai; Ouyang, Zhu

    2013-01-01

    We examined the warming effects on the stomatal frequency, stomatal aperture size and shape, and their spatial distribution pattern of maize (Zea may L.) leaves using a light microscope, an electron scanning microscope, and geostatistic techniques. A field manipulative experiment was conducted to elevate canopy temperature by 2.08°C, on average. We found that experimental warming had little effect on stomatal density, but significantly increased stomatal index due to the reduction in the number of epidermal cells under the warming treatment. Warming also significantly decreased stomatal aperture length and increased stomatal aperture width. As a result, warming significantly increased the average stomatal aperture area and stomatal aperture circumference. In addition, warming dramatically changed the stomatal spatial distribution pattern with a substantial increase in the average nearest neighbor distance between stomata on both adaxial and abaxial surfaces. The spatial distribution pattern of stomata was scale dependent with regular patterns at small scales and random patterns at larger scales on both leaf surfaces. Warming caused the stomatal distribution to become more regular on both leaf surfaces with smaller L(t) values (Ripley's K-function, L(t) is an expectation of zero for any value of t) in the warming plots than the control plots. PMID:24101997

  19. Depth Profiles in Maize ( Zea mays L.) Seeds Studied by Photoacoustic Spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    Photoacoustic spectroscopy (PAS) has been used to analyze agricultural seeds and can be applied to the study of seed depth profiles of these complex samples composed of different structures. The sample depth profile can be obtained through the photoacoustic (PA) signal, amplitude, and phase at different light modulation frequencies. The PA signal phase is more sensitive to changes of thermal properties in layered samples than the PA signal amplitude. Hence, the PA signal phase can also be used to characterize layers at different depths. Thus, the objective of the present study was to obtain the optical absorption spectra of maize seeds ( Zea mays L.) by means of PAS at different light modulation frequencies (17 Hz, 30 Hz, and 50 Hz) and comparing these spectra with the ones obtained from the phase-resolved method in order to separate the optical absorption spectra of seed pericarp and endosperm. The results suggest the possibility of using the phase-resolved method to obtain optical absorption spectra of different seed structures, at different depths, without damaging the seed. Thus, PAS could be a nondestructive method for characterization of agricultural seeds and thus improve quality control in the food industry.

  20. Differential Expression of Superoxide Dismutase Genes in Aphid-Stressed Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

  1. Cloning and characterization of a multifunctional promoter from maize (Zea mays L.).

    PubMed

    Dong, Qing; Jiang, Haiyang; Xu, QianQian; Li, Xiaoming; Peng, Xiaojian; Yu, Haibing; Xiang, Yan; Cheng, Beijiu

    2015-02-01

    The use of tissue-specific promoters to drive the expression of target genes during certain developmental stages or in specific organs can prevent unnecessary gene expression caused by constitutive promoters. Utilizing heterologous promoters to regulate the expression of genes in transgenic receptors can help prevent gene silencing. Here, we engineered heterologous maize promoters that regulate gene-specific expression in rice plant receptors. We performed a histochemical and quantitative β-glucuronidase (GUS) analysis of the Zea mays legumin1 (ZM-LEGF) gene promoter and detailed detection of stably transformed rice expressing the GUS gene under the control of the promoter of ZM-LEGF (pZM-LEGF) and its truncated promoters throughout development. When the promoter sequence was truncated, the location and intensity of GUS expression changed. The results suggest that the sequence from -140 to +41 is a critical region that confers the expression of the entire promoter. Truncation of pZM-LEG (3'-deleted region of pZM-LEGF) markedly increased the GUS activity, with the core cis-elements located in the -273 to -140 regions, namely pZM-LEG6. Detailed analysis of pZM-LEG6::GUS T2 transformant rice seeds and plant tissues at different developmental stages indicated that this promoter is an ideal vegetative tissue-specific promoter that can serve as a valuable tool for transgenic rice breeding and genetic engineering studies. PMID:25391545

  2. Presence of Zea luxurians (Durieu and Ascherson) Bird in Southern Brazil: Implications for the Conservation of Wild Relatives of Maize

    PubMed Central

    2015-01-01

    Records of the occurrence of wild relatives of maize in South American lowlands are unprecedented, especially in sympatric coexistence with landraces. This fact is relevant, because regions of occurrence of wild relatives of cultivated plants should be a priority for conservation, even if they do not correspond to the center of origin of the species. The aim of this study was to identify and characterize the wild relatives of maize in the Far West of Santa Catarina, southern Brazil. Therefore, phenotypic characterization was performed for five populations, based on 22 morphological traits deemed as fundamental for classifying the species of the genus Zea, and validated through the characterization of chromosomal knobs of two populations. The occurrence and distribution of teosinte populations were described through semi-structured interviews applied to a sample of 305 farmers. A total of 136 teosinte populations were identified; 75% of them occur spontaneously, 17% are cultivated populations, and 8% occur both ways, for the same farm. Populations that were characterized morphologically had trapezoidal fruits mostly, upright tassel branch (4–18), non-prominent main branch and glabrous glumes, with two protruding outer ribs and 8 inner ribs, on average. Cytogenetic analysis identified 10 pairs of homologous chromosomes (2n = 20) with 26 knobs, located in the terminal region of all chromosomes. The similarity of these results with the information reported in the literature indicates that the five populations of wild relatives of maize in this region of Santa Catarina belong to the botanical species Zea luxurians. PMID:26488577

  3. Accumulation of 5-hydroxynorvaline in maize (Zea mays) leaves is induced by insect feeding and abiotic stress

    PubMed Central

    Yan, Jian; Lipka, Alexander E.; Schmelz, Eric A.; Buckler, Edward S.; Jander, Georg

    2015-01-01

    Plants produce a wide variety of defensive metabolites to protect themselves against herbivores and pathogens. Non-protein amino acids, which are present in many plant species, can have a defensive function through their mis-incorporation during protein synthesis and/or inhibition of biosynthetic pathways in primary metabolism. 5-Hydroxynorvaline was identified in a targeted search for previously unknown non-protein amino acids in the leaves of maize (Zea mays) inbred line B73. Accumulation of this compound increases during herbivory by aphids (Rhopalosiphum maidis, corn leaf aphid) and caterpillars (Spodoptera exigua, beet armyworm), as well as in response to treatment with the plant signalling molecules methyl jasmonate, salicylic acid and abscisic acid. In contrast, ethylene signalling reduced 5-hydroxynorvaline abundance. Drought stress induced 5-hydroxynorvaline accumulation to a higher level than insect feeding or treatment with defence signalling molecules. In field-grown plants, the 5-hydroxynorvaline concentration was highest in above-ground vegetative tissue, but it was also detectable in roots and dry seeds. When 5-hydroxynorvaline was added to aphid artificial diet at concentrations similar to those found in maize leaves and stems, R. maidis reproduction was reduced, indicating that this maize metabolite may have a defensive function. Among 27 tested maize inbred lines there was a greater than 10-fold range in the accumulation of foliar 5-hydroxynorvaline. Genetic mapping populations derived from a subset of these inbred lines were used to map quantitative trait loci for 5-hydroxynorvaline accumulation to maize chromosomes 5 and 7. PMID:25271262

  4. Accumulation of 5-hydroxynorvaline in maize (Zea mays) leaves is induced by insect feeding and abiotic stress.

    PubMed

    Yan, Jian; Lipka, Alexander E; Schmelz, Eric A; Buckler, Edward S; Jander, Georg

    2015-02-01

    Plants produce a wide variety of defensive metabolites to protect themselves against herbivores and pathogens. Non-protein amino acids, which are present in many plant species, can have a defensive function through their mis-incorporation during protein synthesis and/or inhibition of biosynthetic pathways in primary metabolism. 5-Hydroxynorvaline was identified in a targeted search for previously unknown non-protein amino acids in the leaves of maize (Zea mays) inbred line B73. Accumulation of this compound increases during herbivory by aphids (Rhopalosiphum maidis, corn leaf aphid) and caterpillars (Spodoptera exigua, beet armyworm), as well as in response to treatment with the plant signalling molecules methyl jasmonate, salicylic acid and abscisic acid. In contrast, ethylene signalling reduced 5-hydroxynorvaline abundance. Drought stress induced 5-hydroxynorvaline accumulation to a higher level than insect feeding or treatment with defence signalling molecules. In field-grown plants, the 5-hydroxynorvaline concentration was highest in above-ground vegetative tissue, but it was also detectable in roots and dry seeds. When 5-hydroxynorvaline was added to aphid artificial diet at concentrations similar to those found in maize leaves and stems, R. maidis reproduction was reduced, indicating that this maize metabolite may have a defensive function. Among 27 tested maize inbred lines there was a greater than 10-fold range in the accumulation of foliar 5-hydroxynorvaline. Genetic mapping populations derived from a subset of these inbred lines were used to map quantitative trait loci for 5-hydroxynorvaline accumulation to maize chromosomes 5 and 7. PMID:25271262

  5. Effects of host plant environment and Ustilago maydis infection on the fungal endophyte community of maize (Zea mays).

    PubMed

    Pan, Jean J; Baumgarten, Andrew M; May, Georgiana

    2008-01-01

    The focus of many fungal endophyte studies has been how plants benefit from endophyte infection. Few studies have investigated the role of the host plant as an environment in shaping endophyte community diversity and composition. The effects that different attributes of the host plant, that is, host genetic variation, host variation in resistance to the fungal pathogen Ustilago maydis and U. maydis infection, have on the fungal endophyte communities in maize (Zea mays) was examined. The internal transcribed spacer (ITS) region of the rDNA was sequenced to identify fungi and the endophyte communities were compared in six maize lines that varied in their resistance to U. maydis. It was found that host genetic variation, as determined by maize line, had significant effects on species richness, while the interactions between line and U. maydis infection and line and field plot had significant effects on endophyte community composition. However, the effects of maize line were not dependent on whether lines were resistant or susceptible to U. maydis. Almost 3000 clones obtained from 58 plants were sequenced to characterize the maize endophyte community. These results suggest that the endophyte community is shaped by complex interactions and factors, such as inoculum pool and microclimate, may be important. PMID:18194146

  6. Purification and Partial Characterization of Maize (Zea mays L.) β-Glucosidase

    PubMed Central

    Esen, Asim

    1992-01-01

    Maize (Zea mays L.) β-glucosidase (β-d-glucoside glucohydrolase, EC 3.2.1.21) was extracted from the coleoptiles of 5- to 6-day-old maize seedlings with 50 millimolar sodium acetate, pH 5.0. The pH of the extract was adjusted to 4.6, and most of the contaminating proteins were cryoprecipitated at 0°C for 24 hours. The pH 4.6 supernatant from cryoprecipitation was further fractionated by chromatography on an Accell CM column using a 4.8 to 6.8 pH gradient of 50 millimolar sodium acetate, which yielded the enzyme in two homogeneous, chromatographically different fractions. Purified enzyme was characterized with respect to subunit molecular weight, isoelectric point, amino acid composition, NH2-terminal amino acid sequence, pH and temperature optima, thermostability, and activity and stability in the presence of selected reducing agents, metal ions, and alkylating agents. The purified enzyme has an estimated subunit molecular mass of 60 kilodaltons, isoelectric point at pH 5.2, and pH and temperature optima at 5.8 and 50°C, respectively. The amino acid composition data indicate that the enzyme is rich in Glx and Asx, the sum of which approaches 25%. The sequence of the first 20 amino acids in the N-terminal region was H2N-Ser-Ala-Arg-Val-Gly-Ser-Gln-Asn-Gly-Val-Gln-Met-Leu-Ser-Pro-(Ser?) -Glu-Ile-Pro-Gln, and it shows no significant similarity to other proteins with known sequence. The enzyme is extremely stable at 0 to 4°C up to 1 year but loses activity completely at and above 55°C in 10 minutes. Likewise, the enzyme is stable in the presence of or after treatment with 500 millimolar 2-mercaptoethanol, and it is totally inactivated at 2000 millimolar 2-mercaptoethanol. Such metal ions as Hg2+ and Ag+ reversibly inhibit the enzyme at micromolar concentrations, and inhibition could be completely overcome by adding 2-mercaptoethanol at molar excess of the inhibitory metal ion. The alkylating agents iodoacetic acid and iodoacetamide irreversibly inactivate the

  7. Concurrent Measurements of Oxygen and Carbon Dioxide Exchange during Lightflecks in Maize (Zea mays L.).

    PubMed

    Krall, J. P.; Pearcy, R. W.

    1993-11-01

    Leaves of maize (Zea mays L.) were enclosed in a temperature-controlled cuvette under 35 Pa (350 [mu]bars) CO2 and 0.2 kPa (0.2%)O2 and exposed to short periods (1-30 s) of illumination (light-flecks). The rate and total amount of CO2 assimilated and O2 evolved were measured. The O2 evolution rate was taken as an indicator of the rate of photosynthetic noncyclic electron transport (NCET). In this C4 species, the response of electron transport during the lightflecks qualitatively mimicked that of C3 species previously tested, whereas the response of CO2 assimilation differed. Under short-duration lightflecks at high photon flux density (PFD), the mean rate of O2 evolution was greater than the steady-state rate of O2 evolution under the same PFD due to a burst of O2 evolution at the beginning of the lightfleck. This O2 burst was taken as indicating a high level of NCET involved in the buildup of assimilatory charge via ATP, NADPH, and reduced or phosphorylated metabolites. However, as lightfleck duration decreased, the amount of CO2 assimilated per unit time of the lightfleck (the mean rate of CO2 assimilation) decreased. There was also a burst of CO2 from the leaf at the beginning of low-PFD lightflecks that further reduced the assimilation during these lightflecks. The results are discussed in terms of the buildup of assimilatory charge through the synthesis of high-energy metabolites specific to C4 metabolism. It is speculated that the inefficiency of carbon uptake during brief light transients in the C4 species, relative to C3 species, is due to the futile synthesis of C4 cycle intermediates. PMID:12231981

  8. Proliferation of maize (Zea mays L.) roots in response to localized supply of nitrate

    NASA Technical Reports Server (NTRS)

    Granato, T. C.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    Maize (Zea mays L.) plants with two primary nodal root axes were grown for 8 d in flowing nutrient culture with each axis independently supplied with NO3-. Dry matter accumulation by roots was similar whether 1.0 mol m-3 NO3- was supplied to one or both axes. When NO3- was supplied to only one axis, however, accumulation of dry matter within the root system was significantly greater in the axis supplied with NO3-. The increased dry matter accumulation by the +N-treated axis was attributable entirely to increased density and growth of lateral branches and not to a difference in growth of the primary axis. Proliferation of lateral branches for the +N axis was associated with the capacity for in situ reduction and utilization of a portion of the absorbed NO3-, especially in the apical region where lateral primordia are initiated. Although reduced nitrogen was translocated to the -N axis, concentrations in the -N axis remained significantly lower than in the +N axis. The concentration of reduced nitrogen, as well as in vitro NO3- reductase activity, was greater in apical than in more basal regions of the +N axis. The enhanced proliferation of lateral branches in the +N axis was accompanied by an increase in total respiration rate of the axis. Part of the increased respiration was attributable to increased mass of roots. The specific respiration rate (micromoles CO2 evolved per hour per gram root dry weight) was also greater for the +N than for the -N axis. If respiration rate is taken as representative of sink demand, stimulation of initiation and growth of laterals by in situ utilization of a localized exogenous supply of NO3- establishes an increased sink demand through enhanced metabolic activity and the increased partitioning of assimilates to the +N axis responds to the difference in sink demand between +N and -N axes.

  9. Effect of selenite and selenate on plant uptake of cadmium by maize (zea mays)

    SciTech Connect

    Shanker, K.; Mishra, S.; Srivastava, S.

    1996-03-01

    Selenium has been reported to confer tolerance to toxicity of heavy metals including cadmium, a highly toxic and non essential heavy metal, which enters the food chain via plant uptake from soils. Selenium reduces availability of cadmium to plants along with other aspects of its toxicokinetics. When plants are supplied with selenite, selenium concentrations in the xylem exudate are lower than selenate. Most of the selenate was transported as selenate and unidentified organic Se compounds. In contrast, Se distribution among various Se fractions within plants does not depend significantly on whether selenite or selenate was used. Selenium has a strong tendency to form complexes with heavy metals like Cd, Hg, Ag and Tl. It has been suggested that the protective effects of selenium are due to the formation of non toxic Se-metal complexes, although the mechanism by which this protective effect is exerted remains unclear. Studies on the effect of selenium (selenite) and cadmium additions to the soil on their concentrations in lettuce and wheat has indicated the role of selenite in reduction of cadmium uptake. The cletoxifying effect of sodium selenite on cadmium ion in the freshwater fish Potyacuthus cupanus has been reported. The discovery that an element like selenium counteracts the toxicity, chemical carcinogenesis and reduces the plant uptake of other toxic metals, highlights the possibility of existence of a Se-metal interaction mechanism in soil plant systems. The uptake and translocation of root-absorbed chromium supplied through irrigation in the trivalent and hexavalant states in various parts of the onion plant (Allium cepa) grown in soil and sand culture has been recently reported by us. In continuation of that, this preliminary report describes the effect of selenite and selenate pretreatment on the uptake of cadmium in the maize plant (Zea mays).

  10. Paenibacillus zeae sp. nov., isolated from maize (Zea mays L.) seeds.

    PubMed

    Liu, Yang; Zhai, Lei; Wang, Ronghuan; Zhao, Ran; Zhang, Xin; Chen, Chuanyong; Cao, Yu; Cao, Yanhua; Xu, Tianjun; Ge, Yuanyuan; Zhao, Jiuran; Cheng, Chi

    2015-12-01

    Four Gram-stain-positive bacterial strains, designated 6R2T, 6R18, 3T2 and 3T10, isolated from seeds of hybrid maize (Zea mays L., Jingke 968) were investigated using a polyphasic taxonomic approach. Cells were aerobic, motile, spore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates may represent a novel species of the genus Paenibacillus, the four closest neighbours being Paenibacillus lautus NRRL NRS-666T (97.1 % similarity), Paenibacillus glucanolyticus DSM 5162T (97.0 %), Paenibacillus lactis MB 1871T (97.0 %) and Paenibacillus chibensis JCM 9905T (96.8 %). The DNA G+C content of strain 6R2T was 51.8 mol%. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was menaquinone 7 (MK-7) and the major fatty acids were anteiso-C15 : 0 and iso-C14 : 0. Strains 6R2T, 6R18, 3T2 and 3T10 were clearly distinguished from the above type strains using phylogenetic analysis, DNA-DNA hybridization, and a range of physiological and biochemical characteristics. It is evident from the genotypic and phenotypic data that strains 6R2T, 6R18, 3T2 and 3T10 represent a novel species of the genus Paenibacillus, for which the name Paenibacillus zeae sp. nov. is proposed. The type strain is 6R2T ( = KCTC 33674T = CICC 23860T). PMID:26373452

  11. Finding the joker among the maize endogenous reference genes for genetically modified organism (GMO) detection.

    PubMed

    Paternò, Annalisa; Marchesi, Ugo; Gatto, Francesco; Verginelli, Daniela; Quarchioni, Cinzia; Fusco, Cristiana; Zepparoni, Alessia; Amaddeo, Demetrio; Ciabatti, Ilaria

    2009-12-01

    The comparison of five real-time polymerase chain reaction (PCR) methods targeted at maize ( Zea mays ) endogenous sequences is reported. PCR targets were the alcohol dehydrogenase (adh) gene for three methods and high-mobility group (hmg) gene for the other two. The five real-time PCR methods have been checked under repeatability conditions at several dilution levels on both pooled DNA template from several genetically modified (GM) maize certified reference materials (CRMs) and single CRM DNA extracts. Slopes and R(2) coefficients of all of the curves obtained from the adopted regression model were compared within the same method and among all of the five methods, and the limit of detection and limit of quantitation were analyzed for each PCR system. Furthermore, method equivalency was evaluated on the basis of the ability to estimate the target haploid genome copy number at each concentration level. Results indicated that, among the five methods tested, one of the hmg-targeted PCR systems can be considered equivalent to the others but shows the best regression parameters and a higher repeteability along the dilution range. Thereby, it is proposed as a valid module to be coupled to different event-specific real-time PCR for maize genetically modified organism (GMO) quantitation. The resulting practicability improvement on the analytical control of GMOs is discussed. PMID:19902949

  12. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2016-01-01

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans’ attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

  13. Phosphorus and Compost Management Influence Maize (Zea mays) Productivity Under Semiarid Condition with and without Phosphate Solubilizing Bacteria

    PubMed Central

    Amanullah

    2015-01-01

    Phosphorus (P) unavailability and lack of organic matter in the soils under semiarid climates are the two major constraints for low crop productivity. Field trial was conducted to study the effects of P levels, compost application times and seed inoculation with phosphate solubilizing bacteria (PSB) on the yield and yield components of maize (Zea mays L., cv. Azam). The experiment was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar-Pakistan during summer 2014. The experiment was laid out in randomized complete block design with split plot arrangement using three replications. The two PSB levels [(1) inoculated seed with PSB (+) and (2) seed not inoculated with PSB (- or control)] and three compost application times (30, 15, and 0 days before sowing) combination (six treatments) were used as main plot factor, while four P levels (25, 50, 75, and 100 kg P ha-1) used as subplot factor. The results confirmed that compost applied at sowing time and P applied at the two higher rates (75 and 100 kg P ha-1) had significantly increased yield and yield components of maize under semiarid condition. Maize seed inoculated with PSB (+) had tremendously increased yield and yield components of maize over PSB-control plots (-) under semiarid condition. PMID:26697038

  14. Utilization of maize husk (Zea mays L.) as low-cost adsorbent in removal of iron from aqueous solution.

    PubMed

    Indah, S; Helard, D; Sasmita, A

    2016-01-01

    Adsorption of iron from aqueous solution by using maize husk (Zea mays L.) as a low-cost adsorbent was studied. Batch experiments were carried out at ambient temperature, 0.075-0.250 mm of particle size and 100 rpm of agitation speed to determine the influence of initial pH, adsorbent dose, initial concentration and contact time on the removal of iron. Langmuir and Freundlich models were applied to describe the adsorption isotherm of iron by maize husk. The results showed that optimum condition of iron removal were 4 of pH solution, 20 g/L of adsorbent dose, 10 mg/L of Fe concentration and 15 min of contact time of adsorption with 0.499 mg Fe/g maize husk of adsorption capacity. Experimental data fitted well to Langmuir's adsorption equilibrium isotherm within the concentration range studied. This study demonstrated that maize husk, which is an agricultural waste, has potential for iron removal from groundwater or other polluted waters. PMID:27332838

  15. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    PubMed

    Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method. PMID:25093210

  16. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)

    PubMed Central

    Tian, Yu; Guan, Bo; Zhou, Daowei; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method. PMID:25093210

  17. Environmental materials for remediation of soils contaminated with lead and cadmium using maize (Zea mays L.) growth as a bioindicator.

    PubMed

    Shi, Yu; Huang, Zhanbin; Liu, Xiujie; Imran, Suheryani; Peng, Licheng; Dai, Rongji; Deng, Yulin

    2016-04-01

    Heavy metal pollution is a severe environmental problem. Remediation of contaminated soils can be accomplished using environmental materials that are low cost and environmentally friendly. We evaluated the individual and combination effects of humic acid (HA), super absorbent polymer (SAP), zeolite (ZE), and fly ash composites (FC) on immobilization of lead (Pb) and cadmium (Cd) in contaminated soils. We also investigated long-term practical approaches for remediation of heavy metal pollution in soil. The biochemical and morphological properties of maize (Zea mays L.) were selected as biomarkers to assess the effects of environmental materials on heavy metal immobilization. The results showed that addition of test materials to soil effectively reduced heavy metal accumulation in maize foliage, improving chlorophyll levels, plant growth, and antioxidant enzyme activity. The test materials reduced heavy metal injury to maize throughout the growth period. A synergistic effect from combinations of different materials on immobilization of Pb and Cd was determined based on the reduction of morphological and biochemical injuries to maize. The combination of zeolite and humic acid was especially effective. Treatment with a combination of HA + SAP + ZE + FC was superior for remediation of soils contaminated with high levels of Pb and Cd. PMID:26604199

  18. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings.

    PubMed

    Sytykiewicz, Hubert

    2016-01-01

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans' attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

  19. Direct Mapping Of Density Response in Recombinant Inbred Lines of Maize (Zea mays L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding for adaptation to higher densities in maize has greatly increased maize yield potential per unit area but the genetic basis for this plant response to density is unknown as is its stability over environments. To elucidate the genetic basis of plant response to density in Maize, we mapped QT...

  20. The characterization of ligand-specific maize (Zea mays) profilin mutants.

    PubMed Central

    Kovar, D R; Drøbak, B K; Collings, D A; Staiger, C J

    2001-01-01

    Profilins are low-molecular-mass (12-15 kDa) cytosolic proteins that are major regulators of actin assembly in all eukaryotic cells. In general, profilins from evolutionarily diverse organisms share the ability to bind to G-actin, poly-(L-proline) (PLP) and proline-rich proteins, and polyphosphoinositides. However, the functional importance of each of these interactions remains unclear and might differ between organisms. We investigated the importance of profilin's interaction with its various ligands in plant cells by characterizing four maize (Zea mays) profilin 5 (ZmPRO5) mutants that had single amino acid substitutions in the presumed sites of ligand interaction. Comparisons in vitro with wild-type ZmPRO5 showed that these mutations altered ligand association specifically. ZmPRO5-Y6F had a 3-fold increased affinity for PLP, ZmPRO5-Y6Q had a 5-fold decreased affinity for PLP, ZmPRO5-D8A had a 2-fold increased affinity for PtdIns(4,5)P(2) and ZmPRO5-K86A had a 35-fold decreased affinity for G-actin. When the profilins were microinjected into Tradescantia stamen hair cells, ZmPRO5-Y6F increased the rate of nuclear displacement in stamen hairs, whereas ZmPRO5-K86A decreased the rate. Mutants with a decreased affinity for PLP (ZmPRO5-Y6Q) or an enhanced affinity for PtdIns(4,5)P(2) (ZmPRO5-D8A) were not significantly different from wild-type ZmPRO5 in affecting nuclear position. These results indicate that plant profilin's association with G-actin is extremely important and further substantiate the simple model that profilin acts primarily as a G-actin-sequestering protein in plant cells. Furthermore, interaction with proline-rich binding partners might also contribute to regulating profilin's effect on actin assembly in plant cells. PMID:11485551

  1. Responses of Maize (Zea mays L.) near isogenic lines carrying Wsm1, Wsm2 and Wsm3 to three viruses in the Potyviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three independent genes controlling resistance to Wheat streak mosaic virus (WSMV; family Potyviridae; genus Tritimovirus) were previously identified on chromosomes six (Wsm1), three (Wsm2) and ten (Wsm3) in the resistant maize (Zea mays L.) inbred line Pa405. Near isogenic lines (NIL) carrying eac...

  2. Development of Simple Sequence Repeat Markers from Expressed Sequence Tags of the Maize Gray Leaf Spot Pathogen, Cercospora Zea-Maydis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten simple sequence repeat markers were developed from expressed sequence tags of Cercospora zeae-maydis, the cause of gray leaf spot of maize (Zea mays). All loci were evaluated on 80 isolates from a local population of C. zeae-maydis and all were highly polymorphic, with 4 to 14 alleles per locus....

  3. Effect of minimum tillage and mulching on maize ( Zea mays L.) yield and water content of clayey and sandy soils

    NASA Astrophysics Data System (ADS)

    Mupangwa, Walter; Twomlow, Steve; Walker, Sue; Hove, Lewis

    Rainfed smallholder agriculture in semi-arid areas of southern Africa is subject to numerous constraints. These include low rainfall with high spatial and temporal variability, and significant loss of soil water through evaporation. An experiment was established at Matopos Research Station, Zimbabwe, to determine the effect of mulching and minimum tillage on maize ( Zea mays L.) yield and soil water content. The experiment was run for two years at two sites: clay (Matopos Research Station fields) and sand (Lucydale fields) soils, in a 7 × 3 factorial combination of mulch rates (0, 0.5, 1, 2, 4, 8 and 10 t ha -1) and tillage methods (planting basins, ripper tine and conventional plough). Each treatment was replicated three times at each site in a split plot design. Maize residue was applied as mulch before tillage operations. Two maize varieties, a hybrid (SC 403) and an open pollinated variety (ZM 421), were planted. Maize yield and soil water content (0-30 and 30-60 cm depth) were measured under each treatment. On both soil types, neither mulching nor tillage method had a significant effect on maize grain yield. Tillage methods significantly influenced stover production with planting basins giving the highest stover yield (1.1 t ha -1) on sandy soil and conventional ploughing giving 3.6 t ha -1 on clay soil during the first season. The three tillage methods had no significant effect on seasonal soil water content, although planting basins collected more rainwater during the first half of the cropping period. Mulching improved soil water content in both soil types with maximum benefits observed at 4 t ha -1 of mulch. We conclude that, in the short term, minimum tillage on its own, or in combination with mulching, performs as well as the farmers’ traditional practices of overall ploughing.

  4. 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

  5. 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. PMID:12083257

  6. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    PubMed

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts. PMID:26318006

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

    PubMed

    Sytykiewicz, Hubert

    2016-07-22

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

  8. The circadian clock-associated gene zea mays gigantea1 affects maize developmental transitions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The circadian clock is the internal timing mechanism that allows plants to make developmental decisions in accordance with environmental conditions. The genes of the maize circadian clock are not well defined. Gigantea (gi) genes are conserved across flowering plants, including maize. In model plant...

  9. Characterization of gene expression profiles in developing kernels of maize (Zea mays) inbred Tex6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize oligonuleotide microarray was used to analyze the temporal patterns of gene expression in late developmental maize kernels 25 days after pollination (DAP). There was a total of 57,452 70-mer oligonucleotides on the array. We analyzed gene expression profiles in the developing kernels of Tex6, ...

  10. Comparative analysis of maize (Zea mays) crop performance: natural variation, incremental improvements and economic impacts.

    PubMed

    Leibman, Mark; Shryock, Jereme J; Clements, Michael J; Hall, Michael A; Loida, Paul J; McClerren, Amanda L; McKiness, Zoe P; Phillips, Jonathan R; Rice, Elena A; Stark, Steven B

    2014-09-01

    Grain yield from maize hybrids continues to improve through advances in breeding and biotechnology. Despite genetic improvements to hybrid maize, grain yield from distinct maize hybrids is expected to vary across growing locations due to numerous environmental factors. In this study, we examine across-location variation in grain yield among maize hybrids in three case studies. The three case studies examine hybrid improvement through breeding, introduction of an insect protection trait or introduction of a transcription factor trait associated with increased yield. In all cases, grain yield from each hybrid population had a Gaussian distribution. Across-location distributions of grain yield from each hybrid partially overlapped. The hybrid with a higher mean grain yield typically outperformed its comparator at most, but not all, of the growing locations (a 'win rate'). These results suggest that a broad set of environmental factors similarly impacts grain yields from both conventional- and biotechnology-derived maize hybrids and that grain yields among two or more hybrids should be compared with consideration given to both mean yield performance and the frequency of locations at which each hybrid 'wins' against its comparators. From an economic standpoint, growers recognize the value of genetically improved maize hybrids that outperform comparators in the majority of locations. Grower adoption of improved maize hybrids drives increases in average U.S. maize grain yields and contributes significant value to the economy. PMID:24851925

  11. QTL controlling masculinization of ear tips in a maize (Zea mays L.) intraspecific cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is unique among cereal grasses because of its monoecious flowering habit. Male flowers are normally restricted to the tassel that terminates the primary shoot, whereas female flowers occur as ears at the terminal nodes of lateral branches. We observed a tropical maize inbred, Ki14, that produc...

  12. ANTHOCYANIN CONTENT AND ANTIOXIDANT ACTIVITY IN MAIZE (ZEA MAYS L.) RACES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are maize kernels of different colors including black, blue, red, orange, white and brown. Use of blue and red maize kernels has been increasing, especially in Mexico and Central America, (Betrán et al., 2000). Anthocyanins are the pigments responsible for the blue, black, red and brown colo...

  13. 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

  14. Unraveling the role of dark septate endophyte (DSE) colonizing maize (Zea mays) under cadmium stress: physiological, cytological and genic aspects

    PubMed Central

    Wang, Jun-ling; Li, Tao; Liu, Gao-yuan; Smith, Joshua M.; Zhao, Zhi-wei

    2016-01-01

    A growing body of evidence suggests that plant root-associated fungi such as dark septate endophytes (DSE) can help plants overcome many biotic and abiotic stresses, of great interest is DSE-plant metal tolerance and alleviation capabilities on contaminated soils. However, the tolerance and alleviation mechanisms involved have not yet been elucidated. In the current study, the regulation and physiological response of Zea mays to its root-associated DSE, Exophiala pisciphila was analyzed under increased soil Cd stress (0, 10, 50, 100 mg kg−1). Under Cd stress, DSE inoculation significantly enhanced the activities of antioxidant enzymes and low-molecular weight antioxidants, while also inducing increased Cd accumulation in the cell wall and conversion of Cd into inactive forms by shoot and root specific regulation of genes related to metal uptake, translocation and chelation. Our results showed that DSE colonization resulted in a marked tolerance to Cd, with a significant decrease in cadmium phytotoxicity and a significant increase in maize growth by triggering antioxidant systems, altering metal chemical forms into inactive Cd, and repartitioning subcellular Cd into the cell wall. These results provide comprehensive evidence for the mechanisms by which DSE colonization bioaugments Cd tolerance in maize at physiological, cytological and molecular levels. PMID:26911444

  15. Observation of cytoplasmic and vacuolar malate in maize root tips by sup 13 C-NMR spectroscopy. [Zea mays L

    SciTech Connect

    Chang, K.; Roberts, J.K.M. )

    1989-01-01

    The accumulation of malate by maize (Zea mays L.) root tips perfused with KH{sup 13}CO{sub 3} was followed by {sup 13}C nuclear magnetic resonance spectroscopy. In vivo nuclear magnetic resonance spectra contained distinct signals from two pools of malate in maize root tips, one at a pH {approximately}5.3 (assigned to the vacuole) and one at a pH > 6.5 (assigned to the cytoplasm). The ratio of cytoplasmic to vacuolar malate was lower in 12 millimeter long root tips than in 2 millimeter root tips. The relatively broad width of the signals from C1- and C4-labeled vacuolar malate indicated heterogeneity in vacuolar pH. During the 3 hour KH{sup 13}CO{sub 3} treatment, {sup 13}C-malate accumulated first primarily in the cytoplasm, increasing to a fairly constant level of {approximately}6 millimolar by 1 hour. After a lag, vacuolar malate increased throughout the experiment.

  16. Chromosome elimination and in vivo haploid production induced by Stock 6-derived inducer line in maize (Zea mays L.).

    PubMed

    Zhang, Zili; Qiu, Fazhan; Liu, Yongzhong; Ma, Kejun; Li, Zaiyun; Xu, Shangzhong

    2008-12-01

    In vivo haploid production induced by inducer lines derived from Stock 6 is widely used in breeding program of maize (Zea mays L.), but the mechanisms behind have not yet been fully understood. In this study, average frequency of haploid induction in four inbred lines by Stock 6-derived inducer line HZI1 was above 10%. About 0.2% kernels from the cross Hua24 x HZI1 had mosaic endosperm showing yellow shrunken parts from Hua24 to normal parts with purple aleurone from HZI1. Individual lagged chromosomes and micronuclei were observed in mitotic cells of ovules pollinated by HZI1. Above 56.4% of the radicles from the kernels with purple aleurone and colorless embryos were mixoploid (2n = 9-21), and more than 45.22% cells were haploid cells (2n = 10) in three crosses. More than 62.5% of the radicles from the kernels with purple aleurone and purple embryos were mixoploid (2n = 9-21) having 54.27% cells with 2n = 20. SSR analysis showed that all haploids from the cross Hua24 x HZI1 shared the same genomic compositions as Hua24 except for plants Nos. 862 and 857 with some polymorphic DNA bands. The results revealed that chromosome elimination after fertilization caused the haploid production in maize. PMID:18807046

  17. Unraveling the role of dark septate endophyte (DSE) colonizing maize (Zea mays) under cadmium stress: physiological, cytological and genic aspects.

    PubMed

    Wang, Jun-ling; Li, Tao; Liu, Gao-yuan; Smith, Joshua M; Zhao, Zhi-wei

    2016-01-01

    A growing body of evidence suggests that plant root-associated fungi such as dark septate endophytes (DSE) can help plants overcome many biotic and abiotic stresses, of great interest is DSE-plant metal tolerance and alleviation capabilities on contaminated soils. However, the tolerance and alleviation mechanisms involved have not yet been elucidated. In the current study, the regulation and physiological response of Zea mays to its root-associated DSE, Exophiala pisciphila was analyzed under increased soil Cd stress (0, 10, 50, 100 mg kg(-1)). Under Cd stress, DSE inoculation significantly enhanced the activities of antioxidant enzymes and low-molecular weight antioxidants, while also inducing increased Cd accumulation in the cell wall and conversion of Cd into inactive forms by shoot and root specific regulation of genes related to metal uptake, translocation and chelation. Our results showed that DSE colonization resulted in a marked tolerance to Cd, with a significant decrease in cadmium phytotoxicity and a significant increase in maize growth by triggering antioxidant systems, altering metal chemical forms into inactive Cd, and repartitioning subcellular Cd into the cell wall. These results provide comprehensive evidence for the mechanisms by which DSE colonization bioaugments Cd tolerance in maize at physiological, cytological and molecular levels. PMID:26911444

  18. Evidence for maize (Zea mays) in the Late Archaic (3000–1800 B.C.) in the Norte Chico region of Peru

    PubMed Central

    Haas, Jonathan; Creamer, Winifred; Huamán Mesía, Luis; Goldstein, David; Reinhard, Karl; Rodríguez, Cindy Vergel

    2013-01-01

    For more than 40 y, there has been an active discussion over the presence and economic importance of maize (Zea mays) during the Late Archaic period (3000–1800 B.C.) in ancient Peru. The evidence for Late Archaic maize has been limited, leading to the interpretation that it was present but used primarily for ceremonial purposes. Archaeological testing at a number of sites in the Norte Chico region of the north central coast provides a broad range of empirical data on the production, processing, and consumption of maize. New data drawn from coprolites, pollen records, and stone tool residues, combined with 126 radiocarbon dates, demonstrate that maize was widely grown, intensively processed, and constituted a primary component of the diet throughout the period from 3000 to 1800 B.C. PMID:23440194

  19. Evidence for maize (Zea mays) in the Late Archaic (3000-1800 B.C.) in the Norte Chico region of Peru.

    PubMed

    Haas, Jonathan; Creamer, Winifred; Huamán Mesía, Luis; Goldstein, David; Reinhard, Karl; Rodríguez, Cindy Vergel

    2013-03-26

    For more than 40 y, there has been an active discussion over the presence and economic importance of maize (Zea mays) during the Late Archaic period (3000-1800 B.C.) in ancient Peru. The evidence for Late Archaic maize has been limited, leading to the interpretation that it was present but used primarily for ceremonial purposes. Archaeological testing at a number of sites in the Norte Chico region of the north central coast provides a broad range of empirical data on the production, processing, and consumption of maize. New data drawn from coprolites, pollen records, and stone tool residues, combined with 126 radiocarbon dates, demonstrate that maize was widely grown, intensively processed, and constituted a primary component of the diet throughout the period from 3000 to 1800 B.C. PMID:23440194

  20. Early maize (Zea mays L.) cultivation in Mexico: Dating sedimentary pollen records and its implications

    PubMed Central

    Sluyter, Andrew; Dominguez, Gabriela

    2006-01-01

    A sedimentary pollen sequence from the coastal plain of Veracruz, Mexico, demonstrates maize cultivation by 5,000 years ago, refining understanding of the geography of early maize cultivation. Methodological issues related to bioturbation involved in dating that record combine with its similarity to a pollen sequence from the coastal plain of Tabasco, Mexico, to suggest that the inception of maize cultivation in that record occurred as much as 1,000–2,000 years more recently than the previously accepted 7,000 years ago. Our analysis thereby has substantive, theoretical, and methodological implications for understanding the complex process of maize domestication. Substantively, it demonstrates that the earliest securely dated evidence of maize comes from macrofossils excavated near Oaxaca and Tehuacán, Mexico, and not from the coastal plain along the southern Gulf of Mexico. Theoretically, that evidence best supports the hypothesis that people in the Southern Highlands domesticated this important crop plant. Methodologically, sedimentary pollen and other microfossil sequences can make valuable contributions to reconstructing the geography of early maize cultivation, but we must acknowledge the limits to precision that bioturbation in coastal lagoons imposes on the dating of such records. PMID:16418287

  1. Transcriptome Analysis of Cadmium-Treated Roots in Maize (Zea mays L.)

    PubMed Central

    Yue, Runqing; Lu, Caixia; Qi, Jianshuang; Han, Xiaohua; Yan, Shufeng; Guo, Shulei; Liu, Lu; Fu, Xiaolei; Chen, Nana; Yin, Haiyan; Chi, Haifeng; Tie, Shuanggui

    2016-01-01

    Cadmium (Cd) is a heavy metal and is highly toxic to all plant species. However, the underlying molecular mechanism controlling the effects of auxin on the Cd stress response in maize is largely unknown. In this study, the transcriptome produced by maize ‘Zheng 58’ root responses to Cd stress was sequenced using Illumina sequencing technology. In our study, six RNA-seq libraries yielded a total of 244 million clean short reads and 30.37 Gb of sequence data. A total of 6342 differentially expressed genes (DEGs) were grouped into 908 Gene Ontology (GO) categories and 198 Kyoto Encyclopedia of Genes and Genomes terms. GO term enrichment analysis indicated that various auxin signaling pathway-related GO terms were significantly enriched in DEGs. Comparison of the transcript abundances for auxin biosynthesis, transport, and downstream response genes revealed a universal expression response under Cd treatment. Furthermore, our data showed that free indole-3-acetic acid (IAA) levels were significantly reduced; but IAA oxidase activity was up-regulated after Cd treatment in maize roots. The analysis of Cd activity in maize roots under different Cd and auxin conditions confirmed that auxin affected Cd accumulation in maize seedlings. These results will improve our understanding of the complex molecular mechanisms underlying the response to Cd stress in maize roots.

  2. [Effect of the prolamins in maize (Zea mays L.) grain on tortilla texture].

    PubMed

    Sánchez, F C; Salinas, M Y; Vázquez, C M G; Velázquez, C G A; Aguilar, G N

    2007-09-01

    The prolamins (zeins) are the main storage proteins in the maize grain. There are limited investigations related to their participation on tortilla texture. For determining their effect, normal (6) and Quality Protein Maize (QPM) (6) genotypes were used. The chemical variables comprised prolamins, amylose and starch in whole grain and endosperm. Viscosity of the raw endosperm flour was determined as well as the tortilla texture, expressed in terms of tension force and elongation. Prolamin content in the normal maizes was 64 % higher than that in the QPMs. It was not observed any relationship between prolamin content and flour viscosity. The prolamin content was not related with tortilla hardness, measured as the tension force to rupture the tortilla, but a negative correlation was observed with tortilla elongation. The tortillas with the best texture characteristics were from H-161 nomal maize and H-143 QPM maize, both genotypes showed the smallest grain in its respective gruop. According to the results obtained in the present work, a high prolamin content in maize grain could be affecting tortilla elongation. PMID:18271409

  3. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology.

    PubMed

    Johnston, Robyn; Candela, Héctor; Hake, Sarah; Foster, Toshi

    2010-07-01

    Plant lateral organs, such as leaves, have three primary axes of growth-proximal-distal, medial--lateral and adaxial-abaxial (dorsal-ventral). Although most leaves are planar, modified leaf forms, such as the bikeeled grass prophyll, can be found in nature. A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive mutations in the maize (Zea mays) KANADI (KAN) gene milkweed pod1 (mwp1), which promotes abaxial cell identity, strongly affect development of the prophyll and silks (fused carpels). The prophyll is reduced to two unfused midribs and the silks are narrow and misshapen. Our data indicate that the prophyll and other fused organs are particularly sensitive to disruptions in adaxial-abaxial polarity. In addition, lateral and proximal-distal growth of most lateral organs is reduced in the mwp1-R mutant, supporting a role for the adaxial-abaxial boundary in promoting growth along both axes. We propose that the adaxial-abaxial patterning mechanism has been co-opted during evolution to generate diverse organ morphologies. PMID:20213690

  4. Small kernel 1 encodes a pentatricopeptide repeat protein required for mitochondrial nad7 transcript editing and seed development in maize (Zea mays) and rice (Oryza sativa).

    PubMed

    Li, Xiao-Jie; Zhang, Ya-Feng; Hou, Mingming; Sun, Feng; Shen, Yun; Xiu, Zhi-Hui; Wang, Xiaomin; Chen, Zong-Liang; Sun, Samuel S M; Small, Ian; Tan, Bao-Cai

    2014-09-01

    RNA editing modifies cytidines (C) to uridines (U) at specific sites in the transcripts of mitochondria and plastids, altering the amino acid specified by the DNA sequence. Here we report the identification of a critical editing factor of mitochondrial nad7 transcript via molecular characterization of a small kernel 1 (smk1) mutant in Zea mays (maize). Mutations in Smk1 arrest both the embryo and endosperm development. Cloning of Smk1 indicates that it encodes an E-subclass pentatricopeptide repeat (PPR) protein that is targeted to mitochondria. Loss of SMK1 function abolishes the C → U editing at the nad7-836 site, leading to the retention of a proline codon that is edited to encode leucine in the wild type. The smk1 mutant showed dramatically reduced complex-I assembly and NADH dehydrogenase activity, and abnormal biogenesis of the mitochondria. Analysis of the ortholog in Oryza sativa (rice) reveals that rice SMK1 has a conserved function in C → U editing of the mitochondrial nad7-836 site. T-DNA knock-out mutants showed abnormal embryo and endosperm development, resulting in embryo or seedling lethality. The leucine at NAD7-279 is highly conserved from bacteria to flowering plants, and analysis of genome sequences from many plants revealed a molecular coevolution between the requirement for C → U editing at this site and the existence of an SMK1 homolog. These results demonstrate that Smk1 encodes a PPR-E protein that is required for nad7-836 editing, and this editing is critical to NAD7 function in complex-I assembly in mitochondria, and hence to embryo and endosperm development in maize and rice. PMID:24923534

  5. Impacts of industrial waste resources on maize (Zea mays L.) growth, yield, nutrients uptake and soil properties.

    PubMed

    Singh, Satnam; Young, Li-Sen; Shen, Fo-Ting; Young, Chiu-Chung

    2014-10-01

    Discharging untreated highly acidic (pH<4.0), organic and nutrients rich monosodium glutamate wastewater (MW), and highly alkaline (pH>10.0) paper-mill wastewater (PW) causes environmental pollution. When acidity of MW neutralized (pH 6.5±0.1) with PW and lime (treatments represented as MW+PW and MW+Lime), then MW may be utilized as a potential source of nutrients and organic carbon for sustainable food production. Objectives of this study were to compare the effects of PW and lime neutralized MW and chemical fertilizers on maize (Zea mays L. cv. Snow Jean) plant growth, yield, nutrients uptake, soil organic matter and humic substances. The field experiment was carried out on maize using MW at 6000 L ha(-1). Impacts of the MW application on maize crop and soil properties were evaluated at different stages. At harvest, plant height, and plant N and K uptake were higher in MW treatment. Leaf area index at 60 days after sowing, plant dry matter accumulation at harvest, and kernels ear(-1) and 100-kernel weight were higher in MW+Lime treatment. Kernel N, P, K, Mn, Fe and Zn, and plant Zn uptake were highest in MW+Lime. Plant Fe uptake, and soil organic matter and humic substances were highest in MW+PW. The MW+PW and MW+Lime treatments exhibited comparable results with chemically fertilized treatment. The MW acidity neutralized with lime showed positive impacts on growth, yield and nutrients uptake; nevertheless, when MW pH neutralized with PW has an additional benefit on increase in soil organic matter and humic substances. PMID:24507456

  6. Cadmium toxicity in Maize (Zea mays L.): consequences on antioxidative systems, reactive oxygen species and cadmium accumulation.

    PubMed

    Anjum, Shakeel Ahmad; Tanveer, Mohsin; Hussain, Saddam; Bao, Mingchen; Wang, Longchang; Khan, Imran; Ullah, Ehsan; Tung, Shahbaz Atta; Samad, Rana Abdul; Shahzad, Babar

    2015-11-01

    Increased cadmium (Cd) accumulation in soils has led to tremendous environmental problems, with pronounced effects on agricultural productivity. Present study investigated the effects of Cd stress imposed at various concentrations (0, 75, 150, 225, 300, 375 μM) on antioxidant activities, reactive oxygen species (ROS), Cd accumulation, and productivity of two maize (Zea mays L.) cultivars viz., Run Nong 35 and Wan Dan 13. Considerable variations in Cd accumulation and in behavior of antioxidants and ROS were observed under Cd stress in both maize cultivars, and such variations governed by Cd were concentration dependent. Exposure of plant to Cd stress considerably increased Cd concentration in all plant parts particularly in roots. Wan Dan 13 accumulated relatively higher Cd in root, stem, and leaves than Run Nong 35; however, in seeds, Run Nong 35 recorded higher Cd accumulation. All the Cd toxicity levels starting from 75 μM enhanced H2O2 and MDA concentrations and triggered electrolyte leakage in leaves of both cultivars, and such an increment was more in Run Nong 35. The ROS were scavenged by the enhanced activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione peroxidase in response to Cd stress, and these antioxidant activities were higher in Wan Dan 13 compared with Run Nong 35 at all Cd toxicity levels. The grain yield of maize was considerably reduced particularly for Run Nong 35 under different Cd toxicity levels as compared with control. The Wan Dan 13 was better able to alleviate Cd-induced oxidative damage which was attributed to more Cd accumulation in roots and higher antioxidant activities in this cultivar, suggesting that manipulation of these antioxidants and enhancing Cd accumulation in roots may lead to improvement in Cd stress tolerance. PMID:26122572

  7. An 11-bp Insertion in Zea mays fatb Reduces the Palmitic Acid Content of Fatty Acids in Maize Grain

    PubMed Central

    Li, Qing; Yang, Xiaohong; Zheng, Debo; Warburton, Marilyn; Chai, Yuchao; Zhang, Pan; Guo, Yuqiu; Yan, Jianbing; Li, Jiansheng

    2011-01-01

    The ratio of saturated to unsaturated fatty acids in maize kernels strongly impacts human and livestock health, but is a complex trait that is difficult to select based on phenotype. Map-based cloning of quantitative trait loci (QTL) is a powerful but time-consuming method for the dissection of complex traits. Here, we combine linkage and association analyses to fine map QTL-Pal9, a QTL influencing levels of palmitic acid, an important class of saturated fatty acid. QTL-Pal9 was mapped to a 90-kb region, in which we identified a candidate gene, Zea mays fatb (Zmfatb), which encodes acyl-ACP thioesterase. An 11-bp insertion in the last exon of Zmfatb decreases palmitic acid content and concentration, leading to an optimization of the ratio of saturated to unsaturated fatty acids while having no effect on total oil content. We used three-dimensional structure analysis to explain the functional mechanism of the ZmFATB protein and confirmed the proposed model in vitro and in vivo. We measured the genetic effect of the functional site in 15 different genetic backgrounds and found a maximum change of 4.57 mg/g palmitic acid content, which accounts for ∼20–60% of the variation in the ratio of saturated to unsaturated fatty acids. A PCR-based marker for QTL-Pal9 was developed for marker-assisted selection of nutritionally healthier maize lines. The method presented here provides a new, efficient way to clone QTL, and the cloned palmitic acid QTL sheds lights on the genetic mechanism of oil biosynthesis and targeted maize molecular breeding. PMID:21931818

  8. A novel beta-glucosidase from the cell wall of maize (Zea mays L.): rapid purification and partial characterization

    NASA Technical Reports Server (NTRS)

    Nematollahi, W. P.; Roux, S. J.

    1999-01-01

    Plants have a variety of glycosidic conjugates of hormones, defense compounds, and other molecules that are hydrolyzed by beta-glucosidases (beta-D-glucoside glucohydrolases, E.C. 3.2.1.21). Workers have reported several beta-glucosidases from maize (Zea mays L.; Poaceae), but have localized them mostly by indirect means. We have purified and partly characterized a 58-Ku beta-glucosidase from maize, which we conclude from a partial sequence analysis, from kinetic data, and from its localization is not identical to any of those already reported. A monoclonal antibody, mWP 19, binds this enzyme, and localizes it in the cell walls of maize coleoptiles. An earlier report showed that mWP19 inhibits peroxidase activity in crude cell wall extracts and can immunoprecipitate peroxidase activity from these extracts, yet purified preparations of the 58 Ku protein had little or no peroxidase activity. The level of sequence similarity between beta-glucosidases and peroxidases makes it unlikely that these enzymes share epitopes in common. Contrary to a previous conclusion, these results suggest that the enzyme recognized by mWP19 is not a peroxidase, but there is a wall peroxidase closely associated with the 58 Ku beta-glucosidase in crude preparations. Other workers also have co-purified distinct proteins with beta-glucosidases. We found no significant charge in the level of immunodetectable beta-glucosidase in mesocotyls or coleoptiles that precedes the red light-induced changes in the growth rate of these tissues.

  9. Screening Maize Germplasm for Resistance to Western and Northern Corn Rootworms (Chrysomelidae: Diabrotica spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), with a subterranean larval stage that consumes root tissue. To lessen reliance on soil insecticides and provide alternatives for genetically modified maize hybrids, researchers have developed novel maize germpla...

  10. Effects of Silicon on Photosynthetic Characteristics of Maize (Zea mays L.) on Alluvial Soil

    PubMed Central

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

    2014-01-01

    The objectives of the study were to determine the effects of silicon on photosynthetic characteristics of maize on alluvial soil, including total chlorophyll contents, photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (E), and intercellular CO2 concentration (Ci) using the method of field experiment, in which there were five levels (0, 45, 90, 150, and 225 kg·ha−1) of silicon supplying. The results showed that certain doses of silicon fertilizers can be used successfully in increasing the values of total chlorophyll contents, Pn, and gs and decreasing the values of E and Ci of maize leaves, which meant that photosynthetic efficiency of maize was significantly increased in different growth stages by proper doses of Si application on alluvial soil, and the optimal dose of Si application was 150 kg·ha−1. Our results indicated that silicon in proper amounts can be beneficial in increasing the photosynthetic ability of maize, which would be helpful for the grain yield and growth of maize. PMID:24982984

  11. Overexpression of ARGOS Genes Modifies Plant Sensitivity to Ethylene, Leading to Improved Drought Tolerance in Both Arabidopsis and Maize.

    PubMed

    Shi, Jinrui; Habben, Jeffrey E; Archibald, Rayeann L; Drummond, Bruce J; Chamberlin, Mark A; Williams, Robert W; Lafitte, H Renee; Weers, Ben P

    2015-09-01

    Lack of sufficient water is a major limiting factor to crop production worldwide, and the development of drought-tolerant germplasm is needed to improve crop productivity. The phytohormone ethylene modulates plant growth and development as well as plant response to abiotic stress. Recent research has shown that modifying ethylene biosynthesis and signaling can enhance plant drought tolerance. Here, we report novel negative regulators of ethylene signal transduction in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). These regulators are encoded by the ARGOS gene family. In Arabidopsis, overexpression of maize ARGOS1 (ZmARGOS1), ZmARGOS8, Arabidopsis ARGOS homolog ORGAN SIZE RELATED1 (AtOSR1), and AtOSR2 reduced plant sensitivity to ethylene, leading to enhanced drought tolerance. RNA profiling and genetic analysis suggested that the ZmARGOS1 transgene acts between an ethylene receptor and CONSTITUTIVE TRIPLE RESPONSE1 in the ethylene signaling pathway, affecting ethylene perception or the early stages of ethylene signaling. Overexpressed ZmARGOS1 is localized to the endoplasmic reticulum and Golgi membrane, where the ethylene receptors and the ethylene signaling protein ETHYLENE-INSENSITIVE2 and REVERSION-TO-ETHYLENE SENSITIVITY1 reside. In transgenic maize plants, overexpression of ARGOS genes also reduces ethylene sensitivity. Moreover, field testing showed that UBIQUITIN1:ZmARGOS8 maize events had a greater grain yield than nontransgenic controls under both drought stress and well-watered conditions. PMID:26220950

  12. Assessment of growth and yield losses in two Zea mays L. cultivars (quality protein maize and nonquality protein maize) under projected levels of ozone.

    PubMed

    Singh, Aditya Abha; Agrawal, S B; Shahi, J P; Agrawal, Madhoolika

    2014-02-01

    Rapid industrialization and economic developments have increased the tropospheric ozone (O3) budget since preindustrial times, and presently, it is supposed to be a major threat to crop productivity. Maize (Zea mays L.), a C4 plant is the third most important staple crop at global level with a great deal of economic importance. The present study was conducted to evaluate the performance of two maize cultivars [HQPM1: quality protein maize (QPM)] and [DHM117: nonquality protein maize (NQPM)] to variable O3 doses. Experimental setup included filtered chambers, nonfiltered chambers (NFC), and two elevated doses of O3 viz. NFC+15 ppb O3 (NFC+15) and NFC+30 ppb O3 (NFC+30). During initial growth period, both QPM and NQPM plants showed hormetic effect that is beneficial due to exposure of low doses of a toxicant (NFC and NFC+15 ppb O3), but at later stages, growth attributes were negatively affected by O3. Growth indices showed the variable pattern of photosynthate translocation under O3 stress. Foliar injury in the form of interveinal chlorosis and reddening of leaves due to increased production of anthocyanin pigments was observed at higher concentrations of O3. One-dimensional gel electrophoresis of leaves taken from NFC+30 showed reductions of major photosynthetic proteins, and differential response was observed between the two test cultivars. Decline in the number of male flowers at elevated O3 doses suggested damaging effect of O3 on reproductive structures which might be a cause of productivity losses. Variable carbon allocation pattern particularly to husk leaves, foliar injury, and damage of photosynthetic proteins led to significant reductions in economic yield at higher O3 doses. PCA showed that both the cultivars responded more or less similarly to O3 stress in their respective groupings of growth and yield parameters, but magnitude of their response was variable. It is further supported by difference in the significance of correlations between variables of

  13. Impact of rock materials and biofertilizations on P and K availability for maize (Zea Maize) under calcareous soil conditions.

    PubMed

    Abou-El-Seoud, I I; Abdel-Megeed, A

    2012-01-01

    The present work evaluated the synergistic effects of soil fertilization with rock P and K materials and co-inoculation with P and K-dissolving bacteria [PDB (Bacillus megaterium var. phosphaticum) and KDB (Bacillus mucilaginosus and B. subtilis)] on the improvement of P and K uptake, P and K availability and growth of maize plant grown under limited P and K soil conditions (calcareous soil). The experiment was establishment with eight treatments: without rock P and K materials or bacteria inoculation (control), rock P (RP), rock K (RK), RP + PDB, RK + KDB and R(P + K)+(P + K)DB. Under the same conditions of this study, co-inoculation of PDB and KDB in conjunction with direct application of rock P and K materials (R(P + K)) into the soil increased P and K availability and uptake, and the plant growth (shoot and root growth) of maize plants grown on P and K limited soils. PMID:23961162

  14. Impact of rock materials and biofertilizations on P and K availability for maize (Zea Maize) under calcareous soil conditions

    PubMed Central

    Abou-el-Seoud, I.I.; Abdel-Megeed, A.

    2011-01-01

    The present work evaluated the synergistic effects of soil fertilization with rock P and K materials and co-inoculation with P and K-dissolving bacteria [PDB (Bacillus megaterium var. phosphaticum) and KDB (Bacillus mucilaginosus and B. subtilis)] on the improvement of P and K uptake, P and K availability and growth of maize plant grown under limited P and K soil conditions (calcareous soil). The experiment was establishment with eight treatments: without rock P and K materials or bacteria inoculation (control), rock P (RP), rock K (RK), RP + PDB, RK + KDB and R(P + K)+(P + K)DB. Under the same conditions of this study, co-inoculation of PDB and KDB in conjunction with direct application of rock P and K materials (R(P + K)) into the soil increased P and K availability and uptake, and the plant growth (shoot and root growth) of maize plants grown on P and K limited soils. PMID:23961162

  15. Role of polyamines and phospholipase D in maize (Zea mays L.) response to drought stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydroponic experiment was conducted to elucidate the role of polyamines and phospholipase D (PLD) in regulating response of maize plants to drought stress (DS). During the early stage of DS, an increase in PLD activity, independent of polyamines contents, was mainly responsible for stomatal closure...

  16. Perceptual distinctiveness in Native American maize (Zea mays L.) landraces has practical implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The large variation in the multifactorial and seemingly non-adaptive kernel color trait displayed by Native American maize landraces is an evidence of recurring selection for perceptual distinctiveness. Native American farmers selected for color traits that allowed them to distinguish between and ma...

  17. Production of Feruloyated Arabinoxylo-oligosaccharides from Maize (Zea mays) Bran by Microwave-Assisted Autohydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize bran was treated with microwave irradiation (160 – 200 °C for 2 – 20 min) to release feruolyated arabinoxylo-oligosaccharides (AXOS). Lower temperatures and shorter treatment times were consistent with low AXOS yields, while higher temperatures and longer reaction times also resulted in low y...

  18. Phenolic compounds, carotenoids, anthocyanins, and antioxidant capacity of colored maize (Zea mays L.) kernels.

    PubMed

    Zilić, Slađana; Serpen, Arda; Akıllıoğlu, Gül; Gökmen, Vural; Vančetović, Jelena

    2012-02-01

    In this study, the contents of total phenolics, flavonoids, anthocyanins, β-carotene, and lutein as well as free, conjugated, and insoluble bound phenolic acids were determined in whole kernels of 10 different colored maize genotypes. In addition, the antioxidant activity was evaluated as radical scavenging activity with ABTS (2,2-azino-bis/3-ethil-benothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) reagents. Generally, considerable differences in phytochemical contents and antioxidant capacity were observed between the genotypes. The β-carotene and lutein contents ranged from 0 to 2.42 mg/kg d.m. and from 0 to 13.89 mg/kg d.m., respectively, whereas the total anthocyanin contents of anthocyanin-rich colored maize genotypes ranged from 2.50 to 696.07 mg CGE/kg d.m. (cyanidin 3-glucoside equivalent) with cyanidin 3-glucoside (Cy-3-Glu) as the most dominant form. The light blue ZPP-2 selfed maize genotype has a higher content of total phenolics, flavonoids, and ferulic acid as compared to other tested maize and the highest ABTS radical scavenging activity. PMID:22248075

  19. Maize (Zea mays L) cultivars nutrients concentration in leaves and stalks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is pressure for crop residue removal for use as biofuel, animal feed, animal bedding and many other functions which may increase nutrient export. However, there is little information about nutritional composition of maize stover considering the wide variability of cultivars used. The aim of th...

  20. In vitro pollination of maize (Zea mays L.) - Proof of double fertilization.

    PubMed

    Havel, L; Novák, F J

    1981-08-01

    Isolated ovules from the maize homozygous recessive brown midrib (bm3) were in vitro pollinated by pollen carrying the dominant allele - and the purple embryo marker (PEM). The colour characters of the embryos and kernels corresponded to the results of control pollination and confirmed the process of double fertilization. The question whether the method is useful for obtaining haploids is discussed. PMID:24258750

  1. Isolation, structural analysis, and expression characteristics of the maize (Zea mays L.) hexokinase gene family.

    PubMed

    Zhang, Zhongbao; Zhang, Jiewei; Chen, Yajuan; Li, Ruifen; Wang, Hongzhi; Ding, Liping; Wei, Jianhua

    2014-09-01

    Hexokinases (HXKs, EC 2.7.1.1) play important roles in metabolism, glucose (Glc) signaling, and phosphorylation of Glc and fructose and are ubiquitous in all organisms. Despite their physiological importance, the maize HXK (ZmHXK) genes have not been analyzed systematically. We isolated and characterized nine members of the ZmHXK gene family which were distributed on 3 of the 10 maize chromosomes. A multiple sequence alignment and motif analysis revealed that the maize ZmHXK proteins share three conserved domains. Phylogenetic analysis revealed that the ZmHXK family can be divided into four subfamilies. We identified putative cis-elements in the ZmHXK promoter sequences potentially involved in phytohormone and abiotic stress responses, sugar repression, light and circadian rhythm regulation, Ca(2+) responses, seed development and germination, and CO2-responsive transcriptional activation. To study the functions of maize HXK isoforms, we characterized the expression of the ZmHXK5 and ZmHXK6 genes, which are evolutionarily related to the OsHXK5 and OsHXK6 genes from rice. Analysis of tissue-specific expression patterns using quantitative real time-PCR showed that ZmHXK5 was highly expressed in tassels, while ZmHXK6 was expressed in both tassels and leaves. ZmHXK5 and ZmHXK6 expression levels were upregulated by phytohormones and by abiotic stress. PMID:24962048

  2. Climatic Adaptation and Ecological Descriptors of 42 Mexican Maize (Zea Mays L.) Races

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mexico is the center of diversity of maize. Thousands of collections of farmer varieties have been made in Mexico and these have been grouped into 42 races. We evaluated the ecological adaptation of these races by compiling information on the geography, altitude, temperatures, daylength, and annua...

  3. Development of Single Nucleotide Polymorphism (SNP) Markers for Use in Commercial Maize (Zea Mays L.) Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of single nucleotide polymorphism (SNP) markers in maize offer the opportunity to utilize DNA markers in many new areas of population genetics, gene discovery, plant breeding, and germplasm identification. However, the steps from sequencing and SNP discovery to SNP marker design and ...

  4. Pre-treatment of seeds with static magnetic field ameliorates soil water stress in seedlings of maize (Zea mays L.).

    PubMed

    Anand, Anjali; Nagarajan, Shantha; Verma, A P S; Joshi, D K; Pathak, P C; Bhardwaj, Jyotsna

    2012-02-01

    The effect of magnetic field (MF) treatments of maize (Zea mays L.) var. Ganga Safed 2 seeds on the growth, leaf water status, photosynthesis and antioxidant enzyme system under soil water stress was investigated under greenhouse conditions. The seeds were exposed to static MFs of 100 and 200 mT for 2 and 1 h, respectively. The treated seeds were sown in sand beds for seven days and transplanted in pots that were maintained at -0.03, -0.2 and -0.4 MPa soil water potentials under greenhouse conditions. MF exposure of seeds significantly enhanced all growth parameters, compared to the control seedlings. The significant increase in root parameters in seedlings from magnetically-exposed seeds resulted in maintenance of better leaf water status in terms of increase in leaf water potential, turgor potential and relative water content. Photosynthesis, stomatal conductance and chlorophyll content increased in plants from treated seeds, compared to control under irrigated and mild stress condition. Leaves from plants of magnetically-treated seeds showed decreased levels of hydrogen peroxide and antioxidant defense system enzymes (peroxidases, catalase and superoxide dismutase) under moisture stress conditions, when compared with untreated controls. Mild stress of -0.2 MPa induced a stimulating effect on functional root parameters, especially in 200 mT treated seedlings which can be exploited profitably for rain fed conditions. Our results suggested that MF treatment (100 mT for 2 h and 200 for 1 h) of maize seeds enhanced the seedling growth, leaf water status, photosynthesis rate and lowered the antioxidant defense system of seedlings under soil water stress. Thus, pre sowing static magnetic field treatment of seeds can be effectively used for improving growth under water stress. PMID:22435146

  5. Purification and Characterization of Two Forms of Glutamine Synthetase from the Pedicel Region of Maize (Zea mays L.) Kernels

    PubMed Central

    Muhitch, Michael J.

    1989-01-01

    Maize (Zea mays L.) kernel pedicels, including vascular tissues, pedicel parenchyma, placento-chalazal tissue, and the surrounding pericarp, contained two forms of glutamine synthetase (EC 6.3.1.2), separable by anion exchange chromatography under mildly acidic conditions. The earlier-eluting activity (GSp1), but not the later-eluting activity (GSp2), was chromatographically distinct from the maize leaf and root glutamine synthetases. The level of GSp1 activity changed in a developmentally dependent manner while GSp2 activity was constitutive. GSp1 and GSp2 exhibited distinct ratios of transferase to hydroxylamine-dependent synthetase activities (5 and 23, respectively), which did not change with kernel age. Purified pedicel glutamine synthetases had native relative molecular masses of 340,000, while the subunit relative molecular masses differed slightly at 38,900 and 40,500 for GSp1 and GSp2, respectively. Both GS forms required free Mg2+ with apparent Kms = 2.0 and 0.19 millimolar for GSp1 and GSp2, respectively. GSp1 had an apparent Km for glutamate of 35 millimolar and exhibited substrate inhibition at glutamate concentrations greater than 90 millimolar. In contrast, GSp2 exhibited simple Michaelis-Menten kinetics for glutamate with a Km value of 3.4 millimolar. Both isozymes exhibited positive cooperativity for ammonia, with S0.5 values of 100 and 45 micromolar, respectively. GSp1 appears to be a unique, kernel-specific form of plant glutamine synthetase. Possible functions for the pedicel GS isozymes in kernel nitrogen metabolism are discussed. Images Figure 4 PMID:16667150

  6. Mapping Quantitative Trait Loci Using Naturally Occurring Genetic Variance Among Commercial Inbred Lines of Maize (Zea mays L.)

    PubMed Central

    Zhang, Yuan-Ming; Mao, Yongcai; Xie, Chongqing; Smith, Howie; Luo, Lang; Xu, Shizhong

    2005-01-01

    Many commercial inbred lines are available in crops. A large amount of genetic variation is preserved among these lines. The genealogical history of the inbred lines is usually well documented. However, quantitative trait loci (QTL) responsible for the genetic variances among the lines are largely unexplored due to lack of statistical methods. In this study, we show that the pedigree information of the lines along with the trait values and marker information can be used to map QTL without the need of further crossing experiments. We develop a Monte Carlo method to estimate locus-specific identity-by-descent (IBD) matrices. These IBD matrices are further incorporated into a mixed-model equation for variance component analysis. QTL variance is estimated and tested at every putative position of the genome. The actual QTL are detected by scanning the entire genome. Applying this new method to a well-documented pedigree of maize (Zea mays L.) that consists of 404 inbred lines, we mapped eight QTL for the maize male flowering trait, growing degree day heat units to pollen shedding (GDUSHD). These detected QTL contributed >80% of the variance observed among the inbred lines. The QTL were then used to evaluate all the inbred lines using the best linear unbiased prediction (BLUP) technique. Superior lines were selected according to the estimated QTL allelic values, a technique called marker-assisted selection (MAS). The MAS procedure implemented via BLUP may be routinely used by breeders to select superior lines and line combinations for development of new cultivars. PMID:15716509

  7. Near infrared hyperspectral imaging for the evaluation of endosperm texture in whole yellow maize (Zea maize L.) kernels.

    PubMed

    Manley, Marena; Williams, Paul; Nilsson, David; Geladi, Paul

    2009-10-14

    Near infrared hyperspectral images (HSI) were recorded for whole yellow maize kernels (commercial hybrids) defined as either hard, intermediate, or soft by experienced maize breeders. The images were acquired with a linescan (pushbroom) instrument using a HgCdTe detector. The final image size was 570 x 219 pixels in 239 wavelength bands from 1000 to 2498 nm in steps of approximately 6.5 nm. Multivariate image cleaning was used to remove background and optical errors, in which about two-thirds of all pixels were removed. The cleaned image was used to calculate a principal component analysis (PCA) model after multiplicative scatter correction (MSC) and mean-centering were applied. It was possible to find clusters representing vitreous and floury endosperm (different types of endosperm present in varying ratios in hard and soft kernels) as well as a third type of endosperm by interactively delineating polygon based clusters in the score plot of the second and fourth principal components and projecting the results on the image space. Chemical interpretation of the loading line plots shows the effect of starch density and the protein matrix. The vitreous and floury endosperm clusters were used to make a partial least-squares discriminant analysis (PLS-DA) model, using four components, with a coefficient of determination (R(2)) for the y data (kernel hardness category) for the training set of over 85%. This PLS-DA model could be used for prediction in a test set. We show how the prediction images can be interpreted, thus confirming the validity of the PCA classification. The technique presented here is very powerful for laboratory studies of small cereal samples in order to produce localized information. PMID:19728712

  8. Effect on soil chemistry of genetically modified (GM) vs. non-GM maize.

    PubMed

    Liu, Na; Zhu, Ping; Peng, Chang; Kang, Lingsheng; Gao, Hongjun; Clarke, Nicholas J; Clarke, Jihong Liu

    2010-01-01

    The effects of genetically modified (GM) maize (Zea mays L.) expressing the Bacillus thuringiensis Berliner Cry1Fa2 protein (Bt) and phosphinothricin or glyphosate herbicide tolerance on soil chemistry (organic matter, N, P, K and pH), compared with non-GM controls, were assessed in field and pot experiments. In the field experiment, NH(4)(+) was significantly higher in soil under the crop modified for herbicide tolerance compared to the control (mean values of 11 and 9.6 mg N/kg respectively) while P was significantly higher in soil under the control compared to under the GM crop (mean values of 6.9 and 6.4 dg P/kg, respectively). No significant differences were found as a result of growing Bt/herbicide tolerant maize. In the pot experiment, using soils from three sites (Gongzhuling, Dehui and Huadian), significant effects of using Bt maize instead of conventional maize were found for all three soils. In the Gongzhuling soil, P was significantly higher in soil under the control compared to under the GM crop (mean values of 4.8 and 4.0 dg P/kg, respectively). For the Dehui soil, the pH was significantly higher in soil under the control compared to under the GM crop (mean values for {H(+)} of 1.1 and 2.4 μM for the control and the GM crop respectively). In the Huadian soil, organic matter and total N were both higher in soil under the GM crop than under the control. For organic matter, the mean values were 3.0 and 2.9% for the GM crop and the control, respectively, while for total nitrogen the mean values were 2.02 and 1.96% for the GM crop and the control respectively. Our results indicate that growing GM crops instead of conventional crops may alter soil chemistry, but not greatly, and that effects will vary with both the specific genetic modification and the soil. PMID:21844670

  9. Toxic effects of boron on growth and antioxidant system parameters of maize (Zea mays L.) roots.

    PubMed

    Esim, Nevzat; Tiryaki, Deniz; Karadagoglu, Omer; Atici, Okkes

    2013-10-01

    The aim of this study was to investigate the possible oxidative stress and the antioxidant response, which were caused on maize by boron (B). For this, 11- and 15-day-old maize seedlings were subjected to 2 or 4 mM B in the form of boric acid (H₃BO₃) for 2 and/or 6 days. At the end of the treatment period, root length, hydrogen peroxide (H₂O₂) content, malondialdehyde (MDA) content and the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were measured. The results revealed that root length of plants, activity of antioxidative enzymes such as SOD, POX and CAT and also H₂O₂ contents and MDA levels were seriously affected by excess B. These results suggested that the oxidative stress occurred due to the toxic effect of B. PMID:22491723

  10. Nitrogen transporter and assimilation genes exhibit developmental stage-selective expression in maize (Zea mays L.) associated with distinct cis-acting promoter motifs

    PubMed Central

    Liseron-Monfils, Christophe; Bi, Yong-Mei; Downs, Gregory S; Wu, Wenqing; Signorelli, Tara; Lu, Guangwen; Chen, Xi; Bondo, Eddie; Zhu, Tong; Lukens, Lewis N; Colasanti, Joseph; Rothstein, Steven J; Raizada, Manish N

    2013-01-01

    Nitrogen is considered the most limiting nutrient for maize (Zea mays L.), but there is limited understanding of the regulation of nitrogen-related genes during maize development. An Affymetrix 82K maize array was used to analyze the expression of ≤ 46 unique nitrogen uptake and assimilation probes in 50 maize tissues from seedling emergence to 31 d after pollination. Four nitrogen-related expression clusters were identified in roots and shoots corresponding to, or overlapping, juvenile, adult, and reproductive phases of development. Quantitative real time PCR data was consistent with the existence of these distinct expression clusters. Promoters corresponding to each cluster were screened for over-represented cis-acting elements. The 8-bp distal motif of the Arabidopsis 43-bp nitrogen response element (NRE) was over-represented in nitrogen-related maize gene promoters. This conserved motif, referred to here as NRE43-d8, was previously shown to be critical for nitrate-activated transcription of nitrate reductase (NIA1) and nitrite reductase (NIR1) by the NIN-LIKE PROTEIN 6 (NLP6) in Arabidopsis. Here, NRE43-d8 was over-represented in the promoters of maize nitrate and ammonium transporter genes, specifically those that showed peak expression during early-stage vegetative development. This result predicts an expansion of the NRE-NLP6 regulon and suggests that it may have a developmental component in maize. We also report leaf expression of putative orthologs of nitrite transporters (NiTR1), a transporter not previously reported in maize. We conclude by discussing how each of the four transcriptional modules may be responsible for the different nitrogen uptake and assimilation requirements of leaves and roots at different stages of maize development. PMID:24270626

  11. Identification of QTLs for arsenic accumulation in maize (Zea mays L.) using a RIL population.

    PubMed

    Ding, Dong; Li, Weihua; Song, Guiliang; Qi, Hongyuan; Liu, Jingbao; Tang, Jihua

    2011-01-01

    The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels. PMID:22028786

  12. Leaf physico-chemical and physiological properties of maize (Zea mays L.) populations from different origins.

    PubMed

    Revilla, Pedro; Fernández, Victoria; Álvarez-Iglesias, Lorena; Medina, Eva T; Cavero, José

    2016-10-01

    In this study we evaluated the leaf surface properties of maize populations native to different water availability environments. Leaf surface topography, wettability and gas exchange performance of five maize populations from the Sahara desert, dry (south) and humid (north-western) areas of Spain were analysed. Differences in wettability, stomatal and trichome densities, surface free energy and solubility parameter values were recorded between populations and leaf sides. Leaves from the humid Spanish population with special regard to the abaxial side, were less wettable and less susceptible to polar interactions. The higher wettability and hydrophilicity of Sahara populations with emphasis on the abaxial leaf surfaces, may favour dew deposition and foliar water absorption, hence improving water use efficiency under extremely dry conditions. Compared to the other Saharan populations, the dwarf one had a higher photosynthesis rate suggesting that dwarfism may be a strategy for improving plant tolerance to arid conditions. The results obtained for different maize populations suggest that leaf surfaces may vary in response to drought, but further studies will be required to examine the potential relationship between leaf surface properties and plant stress tolerance. PMID:27368072

  13. Effect of electric arc furnace slag on growth and physiology of maize (Zea mays L.).

    PubMed

    Radić, Sandra; Crnojević, Helena; Sandev, Dubravka; Jelić, Sonja; Sedlar, Zorana; Glavaš, Katarina; Pevalek-Kozlina, Branka

    2013-12-01

    Basic slag, used in this study as a potential source of certain nutrients, is a byproduct of the production of steel in electric arc furnace (EAF). A pot experiment with two nutrient-poor substrates was conducted to investigate to compare the effect of EAF steel slag and fertilizers NPK + F e on growth and availability of specific nutrients to maize. Mineral content of both substrate and plant leaves, growth, chlorophyll fluorescence and photosynthetic pigments were measured following six weeks of cultivation. As steel slag also contains trace amounts of heavy metals, certain oxidative parameters (antioxidative enzyme activities and lipid peroxidation) were evaluated as well. The steel slag improved soil mineral composition, increased above ground maize biomass by providing Fe, Mn, Mg, K and partly P and improved photosynthetic parameters. The potential phytotoxicity of EAF slag containing substrates was not determined as evaluated by MDA (malondialdehyde), GR (glutathione reductase) and APX (ascorbate peroxidase) levels. The obtained results show that EAF steel slag is comparable to NPK + F e in supplying nutrients for maize growth, indicating the potential of EAF steel slag as an inexpensive and non-phytotoxic nutrient supplier especially in poor soils. PMID:24275594

  14. Tissue culture characteristics of maize (Zea mays L.) haploid coleoptile sections.

    PubMed

    Jiang, L; Jing, G X; Li, X Y; Wang, X Q; Xing, Z; Deng, P K; Zhao, R G

    2015-01-01

    Doubled haploid (DH) technology, which is used for rapidly purifying genetic resources, is a key technology in modern maize breeding. The present study evaluated the tissue culture characteristics of maize haploid coleoptile sections, in order to provide a new way of haploid doubling. With 20 combinations of haploid coleoptile sections, obtained by hybridization within Reid, Tangsipingtou, and Term-tropical groups, as explants, we analyzed the induction and differentiation rate of callus, observed the number of root tip chromosomes in regenerated plants, and analyzed the pollen fertility. In addition, we used 47 SSR markers to analyze the genotypes of regenerated plants. The Reid and Tangsipingtou groups had significantly higher induction rates of haploid coleoptile callus compared to the Term-tropical group. Fifteen haploid plants were obtained which had 10 chromosomes in the root tips as assessed by I-KI staining. It was also noticed that the pollen of pollinated anthers were partially fertile. The haploid plants had genetic stability and showed no variation. The Reid and Tangsipingtou groups had good culture characteristics of haploid coleoptile sections, while the Term-tropical group had poor culture characteristics. Genotypes of haploid plants generated by tissue culture were evidenced to come from recombinant types of parents. Thus, this study established a tissue culture system of maize haploid coleoptile. PMID:26662420

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

    PubMed

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

    2015-09-01

    Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The responsiveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses. PMID:25557253

  16. The effect of triazole induced photosynthetic pigments and biochemical constituents of Zea mays L. (Maize) under drought stress

    NASA Astrophysics Data System (ADS)

    Rajasekar, Mahalingam; Rabert, Gabriel Amalan; Manivannan, Paramasivam

    2015-07-01

    In this investigation, pot culture experiment was carried out to estimate the ameliorating effect of triazole compounds, namely Triadimefon (TDM), Tebuconazole (TBZ), and Propiconazole (PCZ) on drought stress, photosynthetic pigments, and biochemical constituents of Zea mays L. (Maize). From 30 days after sowing (DAS), the plants were subjected to 4 days interval drought (DID) stress and drought with TDM at 15 mg l-1, TBZ at 10 mg l-1, and PCZ at 15 mg l-1. Irrigation at 1-day interval was kept as control. Irrigation performed on alternative day. The plant samples were collected on 40, 50, and 60 DAS and separated into root, stem, and leaf for estimating the photosynthetic pigments and biochemical constituents. Drought and drought with triazole compounds treatment increased the biochemical glycine betaine content, whereas the protein and the pigments contents chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, and anthocyanin decreased when compared to control. The triazole treatment mitigated the adverse effects of drought stress by increasing the biochemical potentials and paved the way to overcome drought stress in corn plant.

  17. Occultifur kilbournensis f.a. sp. nov., a new member of the Cystobasidiales associated with maize (Zea mays) cultivation.

    PubMed

    Kurtzman, Cletus P; Robnett, Christie J

    2015-05-01

    During a study of microorganisms associated with maize (Zea mays) cultivation, yeasts were isolated from overwintered stalks, cobs and surrounding soil, which were collected from an agricultural field in south-central Illinois, USA. Predominant among isolates were two species of Cryptococcus (Cr. flavescens, Cr. magnus) and a red yeast that D1/D2 LSU rRNA gene sequences revealed to be a new species of the basidiomycete yeast genus Occultifur. The species, which was not detected in the same field during the growing season, is described here as Occultifur kilbournensis (MycoBank number MB 811259; type strain NRRL Y-63695, CBS 13982, GenBank numbers, D1/D2 LSU rRNA gene, KP413160, ITS, KP413162; allotype strain NRRL Y-63699, CBS 13983). Mixture of the type and allotype strains resulted in formation of hyphae with clamp connections and a small number of apparent basidia following incubation on 5% malt extract agar at 15 °C for 2 months. In view of the uncertainty of the life cycle, the new species is being designated as forma asexualis. From analysis of D1/D2 and ITS nucleotide sequences, the new species is most closely related to Occultifur externus. PMID:25761862

  18. Enhancing the urea-N use efficiency in maize (Zea mays) cultivation on acid soils amended with zeolite and TSP.

    PubMed

    Ahmed, Osumanu H; Hussin, Aminuddin; Ahmad, Husni M H; Rahim, Anuar A; Majid, Nik Muhamad Abd

    2008-01-01

    Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP) and zeolite (Clinoptilolite) on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays) cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives) did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf) production of Swan (test crop). All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea. PMID:18454247

  19. Characteristics and biosynthesis of membrane proteins of lipid bodies in the scutella of maize (Zea mays L.).

    PubMed Central

    Qu, R; Wang, S M; Lin, Y H; Vance, V B; Huang, A H

    1986-01-01

    Storage lipid bodies, which are prominent organelles present in the storage tissues of most seeds, have not been subjected to intensive biochemical investigation. In the present studies the major proteins in lipid bodies isolated from eleven taxonomically diverse species were shown to be distinctly different, as revealed by SDS/polyacrylamide-gel electrophoresis. The lipid-body membrane of maize (Zea mays L.) contained three major proteins of low Mr (19,500, 18,000 and 16,500), and they were chosen for further study. They all had alkaline pI values and behaved as hydrophobic integral proteins, as shown by their resistance to solubilization after repeated washing, amino acid composition and partitioning in a Triton X-114 system. Labelling in vivo with [35S]methionine and translation in vitro using extracted RNA in a wheat-germ system showed that the proteins were synthesized during seed maturation and not germination. The proteins synthesized in vivo and in vitro exhibited no appreciable difference in their mobilities in two-dimensional gel electrophoresis (isoelectric focusing and molecular sieving). The most abundant protein, that of Mr 16,500, was shown to be synthesized predominantly, if not exclusively, by RNA derived from bound polyribosomes and not from free polyribosomes. The implication of the results on the biosynthesis of the lipid bodies is discussed. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:3741390

  20. A two-dimensional microscale model of gas exchange during photosynthesis in maize (Zea mays L.) leaves.

    PubMed

    Retta, Moges; Ho, Quang Tri; Yin, Xinyou; Verboven, Pieter; Berghuijs, Herman N C; Struik, Paul C; Nicolaï, Bart M

    2016-05-01

    CO2 exchange in leaves of maize (Zea mays L.) was examined using a microscale model of combined gas diffusion and C4 photosynthesis kinetics at the leaf tissue level. Based on a generalized scheme of photosynthesis in NADP-malic enzyme type C4 plants, the model accounted for CO2 diffusion in a leaf tissue, CO2 hydration and assimilation in mesophyll cells, CO2 release from decarboxylation of C4 acids, CO2 fixation in bundle sheath cells and CO2 retro-diffusion from bundle sheath cells. The transport equations were solved over a realistic 2-D geometry of the Kranz anatomy obtained from light microscopy images. The predicted responses of photosynthesis rate to changes in ambient CO2 and irradiance compared well with those obtained from gas exchange measurements. A sensitivity analysis showed that the CO2 permeability of the mesophyll-bundle sheath and airspace-mesophyll interfaces strongly affected the rate of photosynthesis and bundle sheath conductance. Carbonic anhydrase influenced the rate of photosynthesis, especially at low intercellular CO2 levels. In addition, the suberin layer at the exposed surface of the bundle sheath cells was found beneficial in reducing the retro-diffusion. The model may serve as a tool to investigate CO2 diffusion further in relation to the Kranz anatomy in C4 plants. PMID:26993234

  1. Influence of temperature stress on in vitro fertilization and heat shock protein synthesis in maize (Zea mays L. ) reproductive tissues

    SciTech Connect

    Dupuis, I.; Dumas, C. )

    1990-10-01

    This study was conducted to investigate the response of maize (Zea mays) male and female mature reproductive tissues to temperature stress. We have tested the fertilization abilities of the stressed spikelets and pollen using in vitro pollination-fertilization to determine their respective tolerance to stress. The synthesis of heat shock proteins (HSPs) was also analyzed in male and female tissues using electrophoresis of {sup 35}S-labeled proteins and fluorography, to establish a relationship between the physiological and molecular responses. Pollen, spikelets, and pollinated spikelets were exposed to selected temperatures (4, 28, 32, 36, or 40{degree}C) and tested using an in vitro fertilization system. The fertilization rate is highly reduced when pollinated spikelets are exposed to temperatures over 36{degree}C. When pollen and spikelets are exposed separately to temperature stress, the female tissues appear resistant to 4 hours of cold stress (4{degree}C) or heat stress (40{degree}C). Under heat shock conditions, the synthesis of a typical set of HSPs is induced in the female tissues. In contrast, the mature pollen is sensitive to heat stress and is responsible for the failure of fertilization at high temperatures. At the molecular level, no heat shock response is detected in the mature pollen.

  2. Changes in photochemical and antioxidant enzyme activities in maize (Zea mays L.) leaves exposed to excess copper.

    PubMed

    Tanyolaç, Deniz; Ekmekçi, Yasemin; Unalan, Seniz

    2007-02-01

    Changes in photosynthetic and antioxidant activities in maize (Zea mays L.) leaves of cultivars 3223 and 31G98 exposed to excess copper (Cu) were investigated. Cu treatment reduced the shoot and root length of both cultivars. No significant difference of Cu accumulation in the roots of both cultivars was observed while the cultivar 3223 accumulated significantly higher Cu in leaves than 31G98. The observed decreases in effective quantum efficiency of PSII, ETR and qP indicate an over excitation of photochemical system in 3223 compared to 31G98. The leaf chlorophyll and carotenoid contents of both cultivars decreased with increasing Cu concentration. A far higher production of anthocyanins in 31G98 has been observed than that of 3223. At 1.5 mM Cu concentration, all antioxidant enzyme activities increased in leaves of the cultivar 31G98 while there were no significant changes in SOD and GR activities in 3223 compared to the control except increased APX and POD activities. The lower Cu accumulation in leaves and higher antioxidant enzyme activities in 31G98 suggested an enhanced tolerance capacity of this cultivar to protect the plant from oxidative damage. PMID:17109927

  3. The effect of triazole induced photosynthetic pigments and biochemical constituents of Zea mays L. (Maize) under drought stress

    NASA Astrophysics Data System (ADS)

    Rajasekar, Mahalingam; Rabert, Gabriel Amalan; Manivannan, Paramasivam

    2016-06-01

    In this investigation, pot culture experiment was carried out to estimate the ameliorating effect of triazole compounds, namely Triadimefon (TDM), Tebuconazole (TBZ), and Propiconazole (PCZ) on drought stress, photosynthetic pigments, and biochemical constituents of Zea mays L. (Maize). From 30 days after sowing (DAS), the plants were subjected to 4 days interval drought (DID) stress and drought with TDM at 15 mg l-1, TBZ at 10 mg l-1, and PCZ at 15 mg l-1. Irrigation at 1-day interval was kept as control. Irrigation performed on alternative day. The plant samples were collected on 40, 50, and 60 DAS and separated into root, stem, and leaf for estimating the photosynthetic pigments and biochemical constituents. Drought and drought with triazole compounds treatment increased the biochemical glycine betaine content, whereas the protein and the pigments contents chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, and anthocyanin decreased when compared to control. The triazole treatment mitigated the adverse effects of drought stress by increasing the biochemical potentials and paved the way to overcome drought stress in corn plant.

  4. Recovery of maize (Zea mays L.) inbreds and hybrids from chilling stress of various duration: photosynthesis and antioxidant enzymes.

    PubMed

    Holá, Dana; Kocová, Marie; Rothová, Olga; Wilhelmová, Nad'a; Benesová, Monika

    2007-07-01

    The differences between two maize (Zea mays L.) inbred lines and their F1 hybrids in their response to chilling periods of various duration (1, 2, 3 or 4 weeks) and subsequent return to optimum temperatures were analysed by the measurement of the photosystem (PS) 1 and 2 activity, the photosynthetic pigments' content and the activity of antioxidant enzymes. The PS2 activity and the chlorophyll content decreased in plants subjected to 3 or 4 weeks of chilling, but not in those subjected to 1 or 2 weeks of chilling. This decrease was more pronounced in inbreds compared to their hybrids. The activity of superoxide dismutase did not much change with the increasing length of chilling period in the inbreds but decreased in the hybrids, the glutathione reductase activity increased in both types of genotypes but more in the inbred lines, while for ascorbate peroxidase and catalase the changes in parents-hybrids relationship did not show any specific trend. The PS1 activity and the carotenoids' content was not much affected. PMID:16884820

  5. Active maize genes are unmodified and flanked by diverse classes of modified, highly repetitive DNA.

    PubMed

    Bennetzen, J L; Schrick, K; Springer, P S; Brown, W E; SanMiguel, P

    1994-08-01

    We have characterized the copy number, organization, and genomic modification of DNA sequences within and flanking several maize genes. We found that highly repetitive DNA sequences were tightly linked to most of these genes. The highly repetitive sequences were not found within the coding regions but could be found within 6 kb either 3' or 5' to the structural genes. These highly repetitive regions were each composed of unique combinations of different short repetitive sequences. Highly repetitive DNA blocks were not interrupted by any detected single copy DNA. The 13 classes of highly repetitive DNA identified were found to vary little between diverse Zea isolates. The level of DNA methylation in and near these genes was determined by scoring the digestibility of 63 recognition/cleavage sites with restriction enzymes that were sensitive to 5-methylation of cytosines in the sequences 5'-CG-3' and 5'-CNG-3'. All but four of these sites were digestible in chromosomal DNA. The four undigested sites were localized to extragenic DNA within or near highly repetitive DNA, while the other 59 sites were in low copy number DNAs. Pulsed field gel analysis indicated that the majority of cytosine modified tracts range from 20 to 200 kb in size. Single copy sequences hybridized to the unmodified domains, while highly repetitive sequences hybridized to the modified regions. Middle repetitive sequences were found in both domains. PMID:7958822

  6. [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. PMID:19602862

  7. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Octenylsuccinic anhydride (OSA)-modified starches with degree of substitution of 0.018 (OS-S-L) and 0.092 (OS-S-H) were prepared from granular native waxy maize starch in an aqueous slurry system. The substitution distribution of OS groups was investigated by enzyme hydrolysis followed by chromatogr...

  8. Reduced crown root number improves water acquisition under water deficit stress in maize (Zea mays L.).

    PubMed

    Gao, Yingzhi; Lynch, Jonathan P

    2016-08-01

    In this study we test the hypothesis that maize genotypes with reduced crown root number (CN) will have greater root depth and improved water acquisition from drying soil. Maize recombinant inbred lines with contrasting CN were evaluated under water stress in greenhouse mesocosms and field rainout shelters. CN varied from 25 to 62 among genotypes. Under water stress in the mesocosms, genotypes with low CN had 31% fewer crown roots, 30% deeper rooting, 56% greater stomatal conductance, 45% greater leaf CO2 assimilation, 61% net canopy CO2 assimilation, and 55% greater shoot biomass than genotypes with high CN at 35 days after planting. Under water stress in the field, genotypes with low CN had 21% fewer crown roots, 41% deeper rooting, 48% lighter stem water oxygen isotope enrichment (δ(18)O) signature signifying deeper water capture, 13% greater leaf relative water content, 33% greater shoot biomass at anthesis, and 57% greater yield than genotypes with high CN. These results support the hypothesis that low CN improves drought tolerance by increasing rooting depth and water acquisition from the subsoil. PMID:27401910

  9. Characterization and expression analysis of six MADS-box genes in maize (Zea mays L.).

    PubMed

    Zhang, Zhongbao; Li, Huiyong; Zhang, Dengfeng; Liu, Yinghui; Fu, Jing; Shi, Yunsu; Song, Yanchun; Wang, Tianyu; Li, Yu

    2012-05-15

    MADS-box genes encode a family of transcription factors, which control diverse developmental processes in flowering plants, with organs ranging from roots, flowers and fruits. In this study, six maize cDNAs encoding MADS-box proteins were isolated. BLASTX searches and phylogenetic analysis indicated that the six MADS-box genes belonging to the AGL2-like clade. qRT-PCR analysis revealed that these genes had differential expression patterns in different organs in maize. The results of yeast one-hybrid system indicated that the protein ZMM3-1, ZMM3-2, ZMM6, ZMM7-L, ZMM8-L and ZMM14-L had transcriptional activation activity. Subcellular localization of ZMM7-L demonstrated that the fluorescence of ZMM7-L-GFP was mainly detected in the nuclei of onion epidermal cells. qRT-PCR analysis for expression pattern of ZMM7-L showed that the gene was up-regulated by abiotic stresses and down-regulated by exogenous ABA. The germination rates of over-expression transgenic lines were lower than that of the wild type on medium with 150 mM NaCl, 350 mM mannitol. These results indicated that ZMM7-L might be a negative transcription factor responsive to abiotic stresses. PMID:22440334

  10. Fungi Isolated from Maize (Zea mays L.) Grains and Production of Associated Enzyme Activities

    PubMed Central

    Lumi Abe, Camila Agnes; Bertechini Faria, Carla; Fernandes de Castro, Fausto; de Souza, Sandra Regina; dos Santos, Fabiane Cristina; Novais da Silva, Cleiltan; Tessmann, Dauri José; Barbosa-Tessmann, Ione Parra

    2015-01-01

    Filamentous fungi produce a great variety of enzymes, and research on their biotechnological potential has recently intensified. The objective of this work was to identify, at the species level, using DNA barcoding, 46 fungal isolates obtained from maize grains with rot symptoms. We also analyzed the production of extracellular amylases, cellulases, proteases and lipases of 33 of those fungal isolates. The enzymatic activities were evaluated by the formation of a clear halo or a white precipitate around the colonies in defined substrate media. The found fungi belong to the genera Talaromyces, Stenocarpella, Penicillium, Phlebiopsis, Cladosporium, Hyphopichia, Epicoccum, Trichoderma, Aspergillus, Irpex, Fusarium, Microdochium, Mucor and Sarocladium. In the genus Fusarium, the species Fusarium verticillioides was predominant and this genus presented the highest diversity, followed by the genera Aspergillus. The best genera for lipase production were Cladosporium and Penicillium; while Cladosporium, Aspergillus and Penicillium were best for cellulase activity; Hyphopichia, Aspergillus and Irpex for amylase activity; and Cladosporium and Sarocladium for proteases activity. In conclusion, a collection of fungi from maize seeds presenting rotten symptoms were obtained, among which exist important producers of hydrolases. PMID:26198227

  11. Reduced crown root number improves water acquisition under water deficit stress in maize (Zea mays L.)

    PubMed Central

    Gao, Yingzhi; Lynch, Jonathan P.

    2016-01-01

    In this study we test the hypothesis that maize genotypes with reduced crown root number (CN) will have greater root depth and improved water acquisition from drying soil. Maize recombinant inbred lines with contrasting CN were evaluated under water stress in greenhouse mesocosms and field rainout shelters. CN varied from 25 to 62 among genotypes. Under water stress in the mesocosms, genotypes with low CN had 31% fewer crown roots, 30% deeper rooting, 56% greater stomatal conductance, 45% greater leaf CO2 assimilation, 61% net canopy CO2 assimilation, and 55% greater shoot biomass than genotypes with high CN at 35 days after planting. Under water stress in the field, genotypes with low CN had 21% fewer crown roots, 41% deeper rooting, 48% lighter stem water oxygen isotope enrichment (δ18O) signature signifying deeper water capture, 13% greater leaf relative water content, 33% greater shoot biomass at anthesis, and 57% greater yield than genotypes with high CN. These results support the hypothesis that low CN improves drought tolerance by increasing rooting depth and water acquisition from the subsoil. PMID:27401910

  12. Organically complexed iron enhances bioavailability of antimony to maize (Zea mays) seedlings in organic soils.

    PubMed

    Ptak, Corey; McBride, Murray

    2015-12-01

    Antimony (Sb) is a metalloid belonging to group 15 of the periodic table. Chemical similarities between arsenic (As) and Sb produce concerns about potential health effects of Sb and enrichment in the environment. Antimony is found in oxic environments predominately as an oxyanionic species, antimonite (Sb[OH](6-)). As a result of its net negative charge, Sb[OH](6-) was not initially predicted to have strong interactions with natural organic matter. Oxyanionic species could bind the negatively charged organic matter via a ternary complexation mechanism, in which cationic metals mediate the strong association between organic matter functional groups and oxyanions. However, these interactions are poorly understood in how they influence the bioavailability of oxyanionic contaminants to plants. Iron (Fe) additions to organic soils have been found to increase the number of organically complexed Fe sites suitable for Sb exchange, resulting in a reduced bioavailable fraction of Sb. The bioavailability of Sb to maize seedlings as a function of organically complexed Fe was examined using a greenhouse study. A significant increase in plant tissue Sb was observed as organically complexed Fe increased, which was not predicted by methods commonly used to assess bioavailable Sb. Extraction of soils with organic acids common to the maize rhizosphere suggested that organic acid exudation can readily mobilize Sb bound by organic Fe complexes. PMID:26076768

  13. Fungi Isolated from Maize (Zea mays L.) Grains and Production of Associated Enzyme Activities.

    PubMed

    Abe, Camila Agnes Lumi; Faria, Carla Bertechini; de Castro, Fausto Fernandes; de Souza, Sandra Regina; dos Santos, Fabiane Cristina; da Silva, Cleiltan Novais; Tessmann, Dauri José; Barbosa-Tessmann, Ione Parra

    2015-01-01

    Filamentous fungi produce a great variety of enzymes, and research on their biotechnological potential has recently intensified. The objective of this work was to identify, at the species level, using DNA barcoding, 46 fungal isolates obtained from maize grains with rot symptoms. We also analyzed the production of extracellular amylases, cellulases, proteases and lipases of 33 of those fungal isolates. The enzymatic activities were evaluated by the formation of a clear halo or a white precipitate around the colonies in defined substrate media. The found fungi belong to the genera Talaromyces, Stenocarpella, Penicillium, Phlebiopsis, Cladosporium, Hyphopichia, Epicoccum, Trichoderma, Aspergillus, Irpex, Fusarium, Microdochium, Mucor and Sarocladium. In the genus Fusarium, the species Fusarium verticillioides was predominant and this genus presented the highest diversity, followed by the genera Aspergillus. The best genera for lipase production were Cladosporium and Penicillium; while Cladosporium, Aspergillus and Penicillium were best for cellulase activity; Hyphopichia, Aspergillus and Irpex for amylase activity; and Cladosporium and Sarocladium for proteases activity. In conclusion, a collection of fungi from maize seeds presenting rotten symptoms were obtained, among which exist important producers of hydrolases. PMID:26198227

  14. Hypoxic stress-induced changes in ribosomes of maize seedling roots. [Zea mays L

    SciTech Connect

    Bailey-Serres, J.; Freeling, M. )

    1990-11-01

    The hypoxic stress response of Zea mays L. seedling roots involves regulation of gene expression at transcriptional and posttranscriptional levels. We investigated the effect of hypoxia on the translational machinery of seedling roots. The levels of monoribosomes and ribosomal subunits increased dramatically within 1 hour of stress. Prolonged hypoxia resulted in continued accumulation of nontranslating ribosomes, as well as increased levels of small polyribosomes. The return of seedlings to normal aerobic conditions resulted in recovery of normal polyribosome levels. Comparison of ribosomal proteins from control and hypoxic roots revealed differences in quantity and electrophoretic mobility. In vivo labeling of roots with ({sup 35}S)methionine revealed variations in newly synthesized ribosomal proteins. In vivo labeling of roots with ({sup 32}P)orthophosphate revealed a major reduction in the phosphorylation of a 31 kilodalton ribosomal protein in hypoxic stressed roots. In vitro phosphorylation of ribosomal proteins by endogenous kinases was used to probe for differences in ribosome structure and composition. The patterns of in vitro kinased phosphoproteins of ribosomes from control and hypoxic roots were not identical. Variation in phosphoproteins of polyribosomes from control and hypoxic roots, as well as among polyribosomes from hypoxic roots were observed. These results indicate that modification of the translational machinery occurs in response to hypoxic stress.

  15. Preparation of cross-linked maize (Zea mays L.) starch in different reaction media.

    PubMed

    Hong, Jung Sun; Gomand, Sara V; Delcour, Jan A

    2015-06-25

    Granular normal maize starch was reacted with sodium trimetaphosphate in deionized water ( [Formula: see text] ), aqueous sodium sulfate solution ( [Formula: see text] ), aqueous ethanol (MSethanol) or aqueous acetone (MSacetone) under otherwise identical reaction conditions. Analysis of the resultant starches by Rapid Visco Analysis (RVA) showed that the starch was cross-linked to a higher degree in aqueous ethanol or aqueous acetone than in water or sodium sulfate solution, and with minimal starch leaching. While MSacetone and MSethanol had incorporated similar levels of phosphorous, RVA analysis and microscopic analysis showed that MSacetone granules were more effectively stabilized by cross-linking than MSethanol granules. Cross-linking in aqueous acetone is believed to either contain the greater numbers of distarch monophosphate (versus monostarch monophosphate), or occur more intensively at the granule outer layers than that in aqueous ethanol and, at the same time, to account for the greater granular strength of MSethanol than that of MSacetone. PMID:25839824

  16. New insights into trophic aerenchyma formation strategy in maize (Zea mays L.) organs during sulfate deprivation

    PubMed Central

    Maniou, Filippa; Chorianopoulou, Styliani N.; Bouranis, Dimitris L.

    2014-01-01

    Aerenchyma attributes plant tissues that contain enlarged spaces exceeding those commonly found as intracellular spaces. It is known that sulfur (S) deficiency leads to formation of aerenchyma in maize adventitious roots by lysis of cortical cells. Seven-day-old maize plants were grown in a hydroponics setup for 19 days under S deprivation against full nutrition. At day 17 and 26 from sowing (d10 and d19 of the deprivation, respectively), a detailed analysis of the total sulfur and sulfate allocation among organs as well as a morphometric characterization were performed. Apart from roots, in S-deprived plants aerenchyma formation was additionally found in the second leaf and in the mesocotyl, too. The lamina (LA) of this leaf showed enlarged gas spaces between the intermediate and small vascular bundles by lysis of mesophyll cells and to a greater extent on the d10 compared to d19. Aerenchymatous spaces were mainly distributed along the middle region of leaf axis. At d10, –S leaves invested less dry mass with more surface area, whilst lesser dry mass was invested per unit surface area in –S LAs. In the mesocotyl, aerenchyma was located near the scutelar node, where mesocotyl roots were developing. In –S roots, more dry mass was invested per unit length. Our data suggest that trying to utilize the available scarce sulfur in an optimal way, the S-deprived plant fine tunes the existing roots with the same length or leaves with more surface area per unit of dry mass. Aerenchyma was not found in the scutelar node and the bases of the attached roots. The sheaths, the LAs’ bases and the crown did not form aerenchyma. This trophic aerenchyma is a localized one, presumably to support new developing tissues nearby, by induced cell death and recycling of the released material. Reduced sulfur allocation among organs followed that of dry mass in a proportional fashion. PMID:25404934

  17. Location of transported auxin in etiolated maize shoots using 5-azidoindole-3-acetic acid. [Zea mays L

    SciTech Connect

    Jones, A.M. )

    1990-07-01

    A study was undertaken using the photoaffinity labeling agent, tritiated 5-azidoindole-3-acetic acid (({sup 3}H),5-N{sub 3}IAA), to identify cells in the etiolated maize (Zea mays L.) shoot which transport auxin. Transport of ({sup 3}H),5-N{sub 3}IAA was shown to be polar, inhibited by 2,3,5-triiodobenzoic acid (TIBA) and essentially freely mobile. There was no detectable radiodecomposition of ({sup 3}H),5-N{sub 3}IAA within tissue kept in darkness for 4 hours. Shoot tissue which had taken up ({sup 3}H),5-N{sub 3}IAA was irradiated with ultraviolet light to covalently fix the photoaffinity labeling agent within cells that contained it at the time of photolysis. Subsequent microautoradiography showed that all cells contained radioactivity; however, the amount of radioactivity varied among different cell types. Epidermal cells contained the most radioactivity per area, approximately twofold more than other cells. Parenchyma cells in the mature stelar region contained the next largest amount and cortical cells, sieve tube cells, tracheary cells, and all cells in the leaf base contained the least amount of the radioactive label. Two observations suggest that the auxin within the epidermal cells is transported in a polar manner: (a) the amount of auxin in the epidermal cells is greatly reduced in the presence of TIBA, and (b) auxin accumulates on the apical side of a wound in the epidermis and is absent on the basal side. While these results indicate that auxin in the epidermis is polarly transported, this tissue cannot be the only pathway since the epidermis is only a small fraction of the shoot volume.

  18. Genetic analysis and molecular mapping of maize (Zea mays L.) stalk rot resistant gene Rfg1.

    PubMed

    Yang, D E; Zhang, C L; Zhang, D S; Jin, D M; Weng, M L; Chen, S J; Nguyen, H; Wang, B

    2004-02-01

    One single pathogen Fusarium graminearum Schw. was inoculated to maize inbred lines 1,145 (Resistant) and Y331 (Susceptive), and their progenies of F(1), F(2) and BC(1)F(1) populations. Field statistical data revealed that all of the F(1) individuals were resistant to the disease and that the ratio of resistant plants to susceptive plants was 3:1 in the F(2) population, and 1:1 in the BC(1)F(1 )population. The results revealed that a single dominant gene controls the resistance to F. graminearum Schw. The resistant gene to F. graminearum Schw. was denominated as Rfg1 according to the standard principle of the nomenclature of the plant disease resistant genes. RAPD (randomly amplified polymorphic DNA) combined with BSA (bulked segregant analysis) analysis was carried out in the developed F(2) and BC(1)F(1 )populations, respectively. Three RAPD products screened from the RAPD analysis with 820 Operon 10-mer primers showed the linkage relation with the resistant gene Rfg1. The three RAPD amplification products (OPD-20(1000), OPA-04(1100) and OPY-04(900)) were cloned and their copy numbers were determined. The results indicated that only OPY-04(900) was a single-copy sequence. Then, OPY-04(900) was used as a probe to map the Rfg1 gene with a RIL F(7) mapping population provided by Henry Nguyen, which was developed from the cross "S3xMo17". Rfg1 was primarily mapped on chromosome 6 between the two linked markers OPY-04(900) and umc21 (Bin 6.04-6.05). In order to confirm the primary mapping result, 25 SSR (simple sequence repeat) markers and six RFLP (restriction fragment length polymorphism) markers in the Rfg1 gene-encompassing region were selected, and their linkage relation with Rfg1 was analyzed in our F(2) population. Results indicated that SSR marker mmc0241 and RFLP marker bnl3.03 are flanking the Rfg1 gene with a genetic distance of 3.0 cM and 2.0 cM, respectively. This is the first time to name and to map a single resistant gene of maize stalk rot through a

  19. Observation of silicon-mediated alleviation of cadmium stress in maize (Zea mays L.) seedlings via LED-induced chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Silva, Elias A.; da Silva, Airon José; do Nascimento, Clístenes W. A.

    2013-02-01

    LED-induced chlorophyll fluorescence analysis is exploited to observe, and monitor the time evolution of silicon-induced alleviation of toxicity in maize (Zea mays L.) seedlings in cadmium contaminated soil. Red, and far-red emissions were examined as a function of cadmium-silicon concentrations, during the 20 days period of the seedlings growing process under stress. The chlorophyll fluorescence spectral analysis provided detection, and evaluation of the damage imposed by the metal stress in the early stages of the plant growing process. The technique also provided the time evolution evaluation of the silicon-induced tolerance enhancement of maize plants to cadmium, which is not viable using conventional in vitro spectral analysis techniques

  20. Prospective Zinc Solubilising Bacteria for Enhanced Nutrient Uptake and Growth Promotion in Maize (Zea mays L.)

    PubMed Central

    Goteti, Praveen Kumar; Emmanuel, Leo Daniel Amalraj; Desai, Suseelendra; Shaik, Mir Hassan Ahmed

    2013-01-01

    Zinc (Zn) is one of the essential micronutrients required for optimum plant growth. Substantial quantity of applied inorganic zinc in soil is converted into unavailable form. Zinc solubilising bacteria are potential alternates for zinc supplement. Among 10 strains screened for Zn solubilisation, P29, P33, and B40 produced 22.0 mm clear haloes on solid medium amended with ZnCO3. Similarly, P17 and B40 showed 31.0 mm zone in ZnO incorporated medium. P29 and B40 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18 and 17 ppm), respectively. The pH of the broth was almost acidic in all the cases ranging from 3.9 to 6.1 in ZnCO3 and from 4.1 to 6.4 in ZnO added medium. Short term pot culture experiment with maize revealed that seed bacterization with P29 @ 10 g·kg−1 significantly enhanced total dry mass (12.96 g) and uptake of N (2.268%), K (2.0%), Mn (60 ppm), and Zn (278.8 ppm). PMID:24489550

  1. Molecular analysis of endophytic bacteria from the genus Bacillus isolated from tropical maize (Zea mays L.)

    PubMed Central

    Figueiredo, José Edson Fontes; Gomes, Eliane Aparecida; Guimarães, Claudia Teixeira; de Paula Lana, Ubiraci Gomes; Teixeira, Marta Aparecida; Lima, Guilherme Vitor Corrêa; Bressan, Wellington

    2009-01-01

    Endophytic bacteria play an important role in agriculture by improving plant performance and adaptation against biotic and abiotic stresses. In the present study molecular methods were used for identifying Bacillus endophytic bacteria isolated from Brazilian sweet corn. SDS-PAGE of whole-cell protein extract of forty-two isolates revealed a high number of scrutinable bands. Twenty-four isolates were identified in nine different groups of duplicated bacteria and eighteen were identified as unique. Some high-accumulated polipeptides with variable length were observed in almost isolates. Partial sequencing of 16S ribosomal gene revealed that all isolates are Bacillus sp. and among thirteen isolates with similar protein profiles, two were different strains. Among the forty-two isolates identified by rDNA sequencing, Bacillus subitilis and B. pumilus were the most frequenty species (15 and 12 isolates, respectively) followed by B. licheniformes (7 isolates), B. cereus (5 isolates) and B. amiloliquefascens (3 isolates). According to present results, SDS-PAGE technique could be used as a fast and cheap first tool for identifying inter-specific variation in maize endophytic bacterial collections while rDNA sequencing could be applied for analyzing intra-specific variation among isolates with similar protein profile as well as for taxonomic studies. PMID:24031395

  2. Lateral root development in the maize (Zea mays) lateral rootless1 mutant

    PubMed Central

    Husakova, Eva; Hochholdinger, Frank; Soukup, Ales

    2013-01-01

    Background and Aims The maize lrt1 (lateral rootless1) mutant is impaired in its development of lateral roots during early post-embryonic development. The aim of this study was to characterize, in detail, the influences that the mutation exerts on lateral root initiation and the subsequent developments, as well as to describe the behaviour of the entire plant under variable environmental conditions. Methods Mutant lrt1 plants were cultivated under different conditions of hydroponics, and in between sheets of moist paper. Cleared whole mounts and anatomical sections were used in combination with both selected staining procedures and histochemical tests to follow root development. Root surface permeability tests and the biochemical quantification of lignin were performed to complement the structural data. Key Results The data presented suggest a redefinition of lrt1 function in lateral roots as a promoter of later development; however, neither the complete absence of lateral roots nor the frequency of their initiation is linked to lrt1 function. The developmental effects of lrt1 are under strong environmental influences. Mutant primordia are affected in structure, growth and emergence; and the majority of primordia terminate their growth during this last step, or shortly thereafter. The lateral roots are impaired in the maintenance of the root apical meristem. The primary root shows disturbances in the organization of both epidermal and subepidermal layers. The lrt1-related cell-wall modifications include: lignification in peripheral layers, the deposition of polyphenolic substances and a higher activity of peroxidase. Conclusions The present study provides novel insights into the function of the lrt1 gene in root system development. The lrt1 gene participates in the spatial distribution of initiation, but not in its frequency. Later, the development of lateral roots is strongly affected. The effect of the lrt1 mutation is not as obvious in the primary root, with no

  3. The Genetic Architecture of Maize (Zea mays L.) Kernel Weight Determination

    PubMed Central

    Prado, Santiago Alvarez; López, César G.; Senior, M. Lynn; Borrás, Lucas

    2014-01-01

    Individual kernel weight is an important trait for maize yield determination. We have identified genomic regions controlling this trait by using the B73xMo17 population; however, the effect of genetic background on control of this complex trait and its physiological components is not yet known. The objective of this study was to understand how genetic background affected our previous results. Two nested stable recombinant inbred line populations (N209xMo17 and R18xMo17) were designed for this purpose. A total of 408 recombinant inbred lines were genotyped and phenotyped at two environments for kernel weight and five other traits related to kernel growth and development. All traits showed very high and significant (P < 0.001) phenotypic variability and medium-to-high heritability (0.60−0.90). When N209xMo17 and R18xMo17 were analyzed separately, a total of 23 environmentally stable quantitative trait loci (QTL) and five epistatic interactions were detected for N209xMo17. For R18xMo17, 59 environmentally stable QTL and 17 epistatic interactions were detected. A joint analysis detected 14 stable QTL regardless of the genetic background. Between 57 and 83% of detected QTL were population specific, denoting medium-to-high genetic background effects. This percentage was dependent on the trait. A meta-analysis including our previous B73xMo17 results identified five relevant genomic regions deserving further characterization. In summary, our grain filling traits were dominated by small additive QTL with several epistatic and few environmental interactions and medium-to-high genetic background effects. This study demonstrates that the number of detected QTL and additive effects for different physiologically related grain filling traits need to be understood relative to the specific germplasm. PMID:25237113

  4. Salicylic Acid and Sodium Salicylate Alleviate Cadmium Toxicity to Different Extents in Maize (Zea mays L.)

    PubMed Central

    Gondor, Orsolya Kinga; Pál, Magda; Darkó, Éva; Janda, Tibor; Szalai, Gabriella

    2016-01-01

    The role of salicylic acid in Cd tolerance has attracted more attention recently but no information is available on the efficiency of different forms of salicylic acid. The aim was thus to investigate whether both the acid and salt forms of salicylic acid provide protection against Cd stress and to compare their mode of action. Young maize plants were grown under controlled environmental conditions. One group of 10-day-old seedlings were treated with 0.5 mM SA or NaSA for 1 day then half of the pants were treated with 0.5 mM Cd for 1 day. Another group of seedlings was treated with 0.5 mM CdSO4 for 1 day without pre-treatment with SA or NaSA, while a third group was treated simultaneously with Cd and either SA or NaSA. Both salicylic acid forms reduced the Cd accumulation in the roots. Treatment with the acidic form meliorated the Cd accumulation in the leaves, while Na-salicylate increased the phytochelatin level in the roots and the amount of salicylic acid in the leaves. Furthermore, increased antioxidant enzyme activity was mainly induced by the acid form, while glutathione-related redox changes were influenced mostly by the salt form. The acidic and salt forms of salicylic acid affected the two antioxidant systems in different ways, and the influence of these two forms on the distribution and detoxification of Cd also differed. The present results also draw attention to the fact that generalisations about the stress protective mechanisms induced by salicylic acid are misleading since different forms of SA may exert different effects on the plants via separate mechanisms. PMID:27490102

  5. Salicylic Acid and Sodium Salicylate Alleviate Cadmium Toxicity to Different Extents in Maize (Zea mays L.).

    PubMed

    Gondor, Orsolya Kinga; Pál, Magda; Darkó, Éva; Janda, Tibor; Szalai, Gabriella

    2016-01-01

    The role of salicylic acid in Cd tolerance has attracted more attention recently but no information is available on the efficiency of different forms of salicylic acid. The aim was thus to investigate whether both the acid and salt forms of salicylic acid provide protection against Cd stress and to compare their mode of action. Young maize plants were grown under controlled environmental conditions. One group of 10-day-old seedlings were treated with 0.5 mM SA or NaSA for 1 day then half of the pants were treated with 0.5 mM Cd for 1 day. Another group of seedlings was treated with 0.5 mM CdSO4 for 1 day without pre-treatment with SA or NaSA, while a third group was treated simultaneously with Cd and either SA or NaSA. Both salicylic acid forms reduced the Cd accumulation in the roots. Treatment with the acidic form meliorated the Cd accumulation in the leaves, while Na-salicylate increased the phytochelatin level in the roots and the amount of salicylic acid in the leaves. Furthermore, increased antioxidant enzyme activity was mainly induced by the acid form, while glutathione-related redox changes were influenced mostly by the salt form. The acidic and salt forms of salicylic acid affected the two antioxidant systems in different ways, and the influence of these two forms on the distribution and detoxification of Cd also differed. The present results also draw attention to the fact that generalisations about the stress protective mechanisms induced by salicylic acid are misleading since different forms of SA may exert different effects on the plants via separate mechanisms. PMID:27490102

  6. Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize (Zea mays L.) lines

    PubMed Central

    Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.; Williams, Daniel L.; Magee, Timothy D.; Kaeppler, Shawn M.; de Leon, Natalia; Hodge, David B.

    2015-01-01

    A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall susceptibility to swelling. It was also positively correlated with the lignin syringyl/guaiacyl ratio and negatively correlated with the initial cell-wall lignin, xylan, acetate, and p-coumaric acid (pCA) content, as well as pCA released from the cell wall by pre-treatment. The hydrolysis yield following pre-treatment exhibited statistically significant negative correlations to the lignin content after pre-treatment and positive correlations to the solubilized ferulic acid and pCA. Several unanticipated results were observed, including a positive correlation between initial lignin and acetate content, lack of correlation between acetate content and initial xylan content, and negative correlation between each of these three variables to the hydrolysis yields for untreated maize. Another surprising result was that pCA release was negatively correlated with hydrolysis yields for untreated maize and, along with ferulic acid release, was positively correlated with the pre-treated maize hydrolysis yields. This indicates that these properties that may negatively contribute to the recalcitrance in untreated cell walls may positively contribute to their deconstruction by alkaline pre-treatment. PMID:25871649

  7. Novel Effects of Nanoparticulate Delivery of Zinc on Growth, Productivity, and Zinc Biofortification in Maize (Zea mays L.).

    PubMed

    Subbaiah, Layam Venkata; Prasad, Tollamadugu Naga Venkata Krishna Vara; Krishna, Thimmavajjula Giridhara; Sudhakar, Palagiri; Reddy, Balam Ravindra; Pradeep, Thalappil

    2016-05-18

    In the present investigation, nanoscale zinc oxide particulates (ZnO-nanoparticulates) were prepared using a modified oxalate decomposition method. Prepared ZnO-nanoparticulates (mean size = 25 nm) were characterized using techniques such as transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and zeta potential analyzer. Different concentrations (50, 100, 200, 400, 600, 800, 1000, 1500, and 2000 ppm) of ZnO-nanoparticulates were examined to reveal their effects on maize crop on overall growth and translocation of zinc along with bulk ZnSO4 and control. Highest germination percentage (80%) and seedling vigor index (1923.20) were observed at 1500 ppm of ZnO-nanoparticulates. The yield was 42% more compared to control and 15% higher compared to 2000 ppm of ZnSO4. Higher accumulation of zinc (35.96 ppm) in grains was recorded with application of 100 ppm followed by 400 ppm (31.05 ppm) of ZnO-nanoparticulates. These results indicate that ZnO-nanoparticulates have significant effects on growth, yield, and zinc content of maize grains, which is an important feature in terms of human health. PMID:27089102

  8. Comparative study of transgenic and non-transgenic maize (Zea mays) flours commercialized in Brazil, focussing on proteomic analyses.

    PubMed

    Vidal, Nádia; Barbosa, Herbert; Jacob, Silvana; Arruda, Marco

    2015-08-01

    Genetically modified foods are a major concern around the world due to the lack of information concerning their safety and health effects. This work evaluates differences, at the proteomic level, between two types of crop samples: transgenic (MON810 event with the Cry1Ab gene, which confers resistance to insects) and non-transgenic maize flour commercialized in Brazil. The 2-D DIGE technique revealed 99 differentially expressed spots, which were collected in 2-D PAGE gels and identified via mass spectrometry (nESI-QTOF MS/MS). The abundance of protein differences between the transgenic and non-transgenic samples could arise from genetic modification or as a result of an environmental influence pertaining to the commercial sample. The major functional category of proteins identified was related to disease/defense and, although differences were observed between samples, no toxins or allergenic proteins were found. PMID:25766830

  9. Silicon modifies root anatomy, and uptake and subcellular distribution of cadmium in young maize plants

    PubMed Central

    Vaculík, Marek; Landberg, Tommy; Greger, Maria; Luxová, Miroslava; Stoláriková, Miroslava; Lux, Alexander

    2012-01-01

    Background and Aims Silicon (Si) has been shown to ameliorate the negative influence of cadmium (Cd) on plant growth and development. However, the mechanism of this phenomenon is not fully understood. Here we describe the effect of Si on growth, and uptake and subcellular distribution of Cd in maize plants in relation to the development of root tissues. Methods Young maize plants (Zea mays) were cultivated for 10 d hydroponically with 5 or 50 µm Cd and/or 5 mm Si. Growth parameters and the concentrations of Cd and Si were determined in root and shoot by atomic absorption spectrometry or inductively coupled plasma mass spectroscopy. The development of apoplasmic barriers (Casparian bands and suberin lamellae) and vascular tissues in roots were analysed, and the influence of Si on apoplasmic and symplasmic distribution of 109Cd applied at 34 nm was investigated between root and shoot. Key Results Si stimulated the growth of young maize plants exposed to Cd and influenced the development of Casparian bands and suberin lamellae as well as vascular tissues in root. Si did not affect the distribution of apoplasmic and symplasmic Cd in maize roots, but considerably decreased symplasmic and increased apoplasmic concentration of Cd in maize shoots. Conclusions Differences in Cd uptake of roots and shoots are probably related to the development of apoplasmic barriers and maturation of vascular tissues in roots. Alleviation of Cd toxicity by Si might be attributed to enhanced binding of Cd to the apoplasmic fraction in maize shoots. PMID:22455991

  10. Field controlled experiments on the physiological responses of maize (Zea mays L.) leaves to low-level air and soil mercury exposures.

    PubMed

    Niu, Zhenchuan; Zhang, Xiaoshan; Wang, Sen; Zeng, Ming; Wang, Zhangwei; Zhang, Yi; Ci, Zhijia

    2014-01-01

    Thousands of tons of mercury (Hg) are released from anthropogenic and natural sources to the atmosphere in a gaseous elemental form per year, yet little is known regarding the influence of airborne Hg on the physiological activities of plant leaves. In the present study, the effects of low-level air and soil Hg exposures on the gas exchange parameters of maize (Zea mays L.) leaves and their accumulation of Hg, proline, and malondialdehyde (MDA) were examined via field open-top chamber and Hg-enriched soil experiments, respectively. Low-level air Hg exposures (<50 ng m(-3)) had little effects on the gas exchange parameters of maize leaves during most of the daytime (p > 0.05). However, both the net photosynthesis rate and carboxylation efficiency of maize leaves exposed to 50 ng m(-3) air Hg were significantly lower than those exposed to 2 ng m(-3) air Hg in late morning (p < 0.05). Additionally, the Hg, proline, and MDA concentrations in maize leaves exposed to 20 and 50 ng m(-3) air Hg were significantly higher than those exposed to 2 ng m(-3) air Hg (p < 0.05). These results indicated that the increase in airborne Hg potentially damaged functional photosynthetic apparatus in plant leaves, inducing free proline accumulation and membrane lipid peroxidation. Due to minor translocation of soil Hg to the leaves, low-level soil Hg exposures (<1,000 ng g(-1)) had no significant influences on the gas exchange parameters, or the Hg, proline, and MDA concentrations in maize leaves (p > 0.05). Compared to soil Hg, airborne Hg easily caused physiological stress to plant leaves. The effects of increasing atmospheric Hg concentration on plant physiology should be of concern. PMID:23943002

  11. Contribution of arbuscular mycorrhizal fungi to the development of maize (Zea mays L.) grown in three types of coal mine spoils.

    PubMed

    Guo, Wei; Zhao, Renxin; Fu, Ruiying; Bi, Na; Wang, Lixin; Zhao, Wenjing; Guo, Jiangyuan; Zhang, Jun

    2014-03-01

    Coal mine spoils are usually unfavorable for plant growth and have different properties according to dumping years, weathering degree, and the occurrence of spontaneous combustion. The establishment of plant cover in mine spoils can be facilitated by arbuscular mycorrhizal fungi (AMF). A greenhouse pot experiment was conducted to evaluate the importance of AMF in plant adaptation to different mine spoils and the potential role of AMF for revegetation practices. We investigated the effects of Glomus aggregatum, Rhizophagus intraradices (syn. Glomus intraradices), and Funneliformis mosseae (syn. Glomus mosseae) on the growth, nutritional status, and metal uptake of maize (Zea mays L.) grown in recent discharged (S1), weathered (S2), and spontaneous combusted (S3) coal mine spoils. Symbiotic associations were successfully established between AMF and maize in three substrates. Mycorrhizal colonization effectively promoted plant growth by significantly increasing the uptake of nitrogen (N), phosphorus (P), and potassium (K), adjusting C:N:P stoichiometry and alleviating toxic effects of heavy metals. G. aggregatum, R. intraradices, and F. mosseae exhibited different mycorrhizal effects in response to mine spoil types. F. mosseae was the most effective in the development of maize in S1 and may be the most appropriate for revegetation of this substrate, while R. intraradices played the most beneficial role in S2 and S3. Our results suggest that inoculation with AMF can enhance plant adaptation to different types of coal mine spoils and play a positive role in the revegetation of coal mine spoil banks. PMID:24271733

  12. 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. PMID:11383153

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Identification and expression profiling analysis of calmodulin-binding transcription activator genes in maize (Zea mays L.) under abiotic and biotic stresses

    PubMed Central

    Yue, Runqing; Lu, Caixia; Sun, Tao; Peng, Tingting; Han, Xiaohua; Qi, Jianshuang; Yan, Shufeng; Tie, Shuanggui

    2015-01-01

    The calmodulin-binding transcription activators (CAMTA) play critical roles in plant growth and responses to environmental stimuli. However, how CAMTAs function in responses to abiotic and biotic stresses in maize (Zea mays L.) is largely unknown. In this study, we first identified all the CAMTA homologous genes in the whole genome of maize. The results showed that nine ZmCAMTA genes showed highly diversified gene structures and tissue-specific expression patterns. Many ZmCAMTA genes displayed high expression levels in the roots. We then surveyed the distribution of stress-related cis-regulatory elements in the −1.5 kb promoter regions of ZmCAMTA genes. Notably, a large number of stress-related elements present in the promoter regions of some ZmCAMTA genes, indicating a genetic basis of stress expression regulation of these genes. Quantitative real-time PCR was used to test the expression of ZmCAMTA genes under several abiotic stresses (drought, salt, and cold), various stress-related hormones [abscisic acid, auxin, salicylic acid (SA), and jasmonic acid] and biotic stress [rice black-streaked dwarf virus (RBSDV) infection]. Furthermore, the expression pattern of ZmCAMTA genes under RBSDV infection was analyzed to investigate their potential roles in responses of different maize cultivated varieties to RBSDV. The expression of most ZmCAMTA genes responded to both abiotic and biotic stresses. The data will help us to understand the roles of CAMTA-mediated Ca2+ signaling in maize tolerance to environmental stresses. PMID:26284092

  15. Provitamin A potential of landrace orange maize variety (Zea mays L.) grown in different geographical locations of central Malawi.

    PubMed

    Hwang, Taeyoung; Ndolo, Victoria U; Katundu, Mangani; Nyirenda, Blessings; Bezner-Kerr, Rachel; Arntfield, Susan; Beta, Trust

    2016-04-01

    The provitamin A potential of landrace orange maize from different locations (A, B, C and D) of central Malawi has been evaluated. Physicochemical compositions, color, total carotenoid content (TCC), carotenoid profiles, and oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity as antioxidant capacities of maize were determined. Color values of orange maize had correlations with β-cryptoxanthin (r>0.36). TCC of white and orange maize averaged 2.12 and 59.5 mg/kg, respectively. Lutein was the most abundant carotenoid (47.8%) in orange maize, followed by zeaxanthin (24.2%), β-carotene (16.4%) and β-cryptoxanthin (11.6%). Location D showed the highest levels of lutein, zeaxanthin and antioxidant capacity. Provitamin A content of orange maize met the target level (15 μg/g) of biofortification. Retinol activity equivalent (RAE) from β-cryptoxanthin and β-carotene in orange maize averaged 81.73 μg/100g. In conclusion, orange maize has the potential to be a natural source of provitamin A. PMID:26593622

  16. The selection and use of sorghum (Sorghum propinquum) bacterial artificial chromosomes as cytogenetic FISH probes for maize (Zea mays L.).

    PubMed

    Figueroa, Debbie M; Davis, James D; Strobel, Cornelia; Conejo, Maria S; Beckham, Katherine D; Ring, Brian C; Bass, Hank W

    2011-01-01

    The integration of genetic and physical maps of maize is progressing rapidly, but the cytogenetic maps lag behind, with the exception of the pachytene fluorescence in situ hybridization (FISH) maps of maize chromosome 9. We sought to produce integrated FISH maps of other maize chromosomes using Core Bin Marker loci. Because these 1 Kb restriction fragment length polymorphism (RFLP) probes are below the FISH detection limit, we used BACs from sorghum, a small-genome relative of maize, as surrogate clones for FISH mapping. We sequenced 151 maize RFLP probes and compared in silico BAC selection methods to that of library filter hybridization and found the latter to be the best. BAC library screening, clone verification, and single-clone selection criteria are presented along with an example of transgenomic BAC FISH mapping. This strategy has been used to facilitate the integration of RFLP and FISH maps in other large-genome species. PMID:21234422

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

    PubMed

    Heckmann, Lars-Henrik; Griffiths, Bryan S; Caul, Sandra; Thompson, Jacqueline; Pusztai-Carey, Marianne; Moar, William J; Andersen, Mathias N; Krogh, Paul Henning

    2006-07-01

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. PMID:16310913

  18. Selection and adaptation to high plant density in the Iowa Stiff Stalk synthetic maize (Zea mays L.) population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant density at which Zea mays L. hybrids achieve maximum grain yield has increased throughout the hybrid era while grain yield on a per plant basis has increased little. Changes in plant traits including grain yield, moisture, test weight, and stalk and root lodging have been well characterize...

  19. Uptake, translocation and biotransformation kinetics of BDE-47, 6-OH-BDE-47 and 6-MeO-BDE-47 in maize (Zea mays L.).

    PubMed

    Xu, Xuehui; Wen, Bei; Huang, Honglin; Wang, Sen; Han, Ruixia; Zhang, Shuzhen

    2016-01-01

    This study presents a detailed kinetic investigation on the uptake, acropetal translocation and transformation of BDE-47, 6-OH-BDE-47 and 6-MeO-BDE-47 in maize (Zea mays L.) by hydroponic exposure. Root uptake followed the order: BDE-47 > 6-MeO-BDE-47 > 6-OH-BDE-47, while 6-OH-BDE-47 was the most prone to acropetal translocation. Debromination rates of BDE-47 were 1.31 and 1.46 times greater than the hydroxylation and methoxylation rates, respectively. Transformation from BDE-47 to lower brominated OH/MeO-PBDEs occurred mainly through debromination first followed by hydroxylation or methoxylation. There was no transformation from 6-OH-BDE-47 or 6-MeO-BDE-47 to PBDEs. Methylation rate of 6-OH-BDE-47 was twice as high as that of 6-MeO-BDE-47 hydroxylation, indicating methylation of 6-OH-BDE-47 was easier and more rapid than hydroxylation of 6-MeO-BDE-47. Debromination and isomerization were potential metabolic pathways for 6-OH-BDE-47 and 6-MeO-BDE-47 in maize. This study provides important information for better understanding the mechanism on plant uptake and transformation of PBDEs. PMID:26561454

  20. Effect of Piriformospora indica inoculation on root development and distribution of maize (Zea mays L.) in the presence of petroleum contaminated soil

    NASA Astrophysics Data System (ADS)

    Zamani, Javad; Hajabbasi, Mohammad Ali; Alaie, Ebrahim

    2014-05-01

    The root systems of most terrestrial plants are confronted to various abiotic and biotic stresses. One of these abiotic stresses is contamination of soil with petroleum hydrocarbon, which the efficiency of phytoremediation of petroleum hydrocarbons in soils is dependent on the ability of plant roots to development into the contaminated soils. Piriformospora indica represents a recently discovered fungus that transfers considerable beneficial impact to its host plants. A rhizotron experiment was conducted to study the effects of P. Indica inoculation on root distribution and root and shoot development of maize (Zea mays L.) in the presence of three patterns of petroleum contamination in the soil (subsurface contamination, continuous contamination and without contamination (control)). Root distribution and root and shoot development were monitored over time. The final root and shoot biomass and the final TPH concentration in the rhizosphere were determined. Analysis of digitized images which were prepared of the tracing of the appeared roots along the front rhizotrons showed the depth and total length of root network in the contamination treatments were significantly decreased. Although the degradation of TPH in the rhizosphere of maize was significant, but there were no significant differences between degradation of TPH in the rhizosphere of +P. indica plants in comparison to -P. indica plants.

  1. The determination of physiological and DNA changes in seedlings of maize (Zea mays L.) seeds exposed to the waters of the Gediz River and copper heavy metal stress.

    PubMed

    Batir, Muhammet Burak; Candan, Feyza; Buyuk, Ilker; Aras, Sumer

    2015-04-01

    In this study, the effects of the heavy metal-polluted waters of the Gediz River, which flow into the Aegean Sea, and different concentrations of copper (Cu) solutions on maize (Zea mays L.) seedlings are investigated with physiological parameters and random amplified polymorphic DNA (RAPD) assay. Results displayed physiologically a significant difference in root and stem length between the control seedlings and the seedlings grown with the waters of the Gediz River. Also, the certain ascending concentrations of copper solution (80, 160, 320, 640, and 1280 ppm) caused a significant decrease in root and stem length of seedlings compared to the control seedlings. As a result of the waters of the Gediz River and copper solution treatment, the changes occurred in RAPD profiles of seedlings observed as variations like increment and/or loss of bands compared with the control seedlings. And these changes were reflected as a decrease in genomic template stability (GTS, changes in RAPD profile) derived by genotoxicity. RAPD band profiles and GTS values showed consistent results with physiological parameter. In conclusion, the study revealed the environmental risk and negative effect of waters of the Gediz River on maize seedlings and the suitability of RAPD assay for the detection of environmental toxicology. PMID:25750069

  2. Detection of genetically modified maize and soybean in feed samples.

    PubMed

    Meriç, S; Cakır, O; Turgut-Kara, N; Arı, S

    2014-01-01

    Despite the controversy about genetically modified (GM) plants, they are still incrementally cultivated. In recent years, many food and feed products produced by genetic engineering technology have appeared on store shelves. Controlling the production and legal presentation of GM crops are very important for the environment and human health, especially in terms of long-term consumption. In this study, 11 kinds of feed obtained from different regions of Turkey were used for genetic analysis based on foreign gene determination. All samples were screened by conventional polymerase chain reaction (PCR) technique for widely used genetic elements; cauliflower mosaic virus 35S promoter (CaMV35S promoter), and nopaline synthase terminator (T-NOS) sequences for GM plants. After determination of GM plant-containing samples, nested PCR and conventional PCR analysis were performed to find out whether the samples contained Bt176 or GTS-40-3-2 for maize and soy, respectively. As a result of PCR-based GM plant analysis, all samples were found to be transgenic. Both 35S- and NOS-containing feed samples or potentially Bt176-containing samples, in other words, were analyzed with Bt176 insect resistant cryIAb gene-specific primers via nested PCR. Eventually, none of them were found Bt176-positive. On the other hand, when we applied conventional PCR to the same samples with the herbicide resistance CTP4-EPSPS construct-specific primers for transgenic soy variety GTS-40-3-2, we found that all samples were positive for GTS-40-3-2. PMID:24634172

  3. The influence of fertilizer level and spore density on arbuscular mycorrhizal colonization of transgenic Bt 11 maize (Zea mays) in experimental microcosms.

    PubMed

    Cheeke, Tanya E; Pace, Brian A; Rosenstiel, Todd N; Cruzan, Mitchell B

    2011-02-01

    Crop plants genetically modified for the expression of Bacillus thuringiensis (Bt) insecticidal toxins have broad appeal for reducing insect damage in agricultural systems, yet questions remain about the impact of Bt plants on symbiotic soil organisms. Here, arbuscular mycorrhizal fungal (AMF) colonization of transgenic maize isoline Bt 11 (expressing Cry1Ab) and its non-Bt parental line (Providence) was evaluated under different fertilizer level and spore density scenarios. In a three-way factorial design, Bt 11 and non-Bt maize were inoculated with 0, 40, or 80 spores of Glomus mosseae and treated weekly with 'No' (0 g L(-1) ), 'Low' (0.23 g L(-1) ), or 'High' (1.87 g L(-1) ) levels of a complete fertilizer and grown for 60 days in a greenhouse. While no difference in AMF colonization was detected between the Bt 11 and Providence maize cultivars in the lower spore/higher fertilizer treatments, microcosm experiments demonstrated a significant reduction in AMF colonization in Bt 11 maize roots in the 80 spore treatments when fertilizer was limited. These results confirm previous work indicating an altered relationship between this Bt 11 maize isoline and AMF and demonstrate that the magnitude of this response is strongly dependent on both nutrient supply and AMF spore inoculation level. PMID:21198682

  4. Three groups of transposable elements with contrasting copy number dynamics and host responses in the maize (Zea mays ssp. mays) genome.

    PubMed

    Diez, Concepcion M; Meca, Esteban; Tenaillon, Maud I; Gaut, Brandon S

    2014-04-01

    Most angiosperm nuclear DNA is repetitive and derived from silenced transposable elements (TEs). TE silencing requires substantial resources from the plant host, including the production of small interfering RNAs (siRNAs). Thus, the interaction between TEs and siRNAs is a critical aspect of both the function and the evolution of plant genomes. Yet the co-evolutionary dynamics between these two entities remain poorly characterized. Here we studied the organization of TEs within the maize (Zea mays ssp mays) genome, documenting that TEs fall within three groups based on the class and copy numbers. These groups included DNA elements, low copy RNA elements and higher copy RNA elements. The three groups varied statistically in characteristics that included length, location, age, siRNA expression and 24:22 nucleotide (nt) siRNA targeting ratios. In addition, the low copy retroelements encompassed a set of TEs that had previously been shown to decrease expression within a 24 nt siRNA biogenesis mutant (mop1). To investigate the evolutionary dynamics of the three groups, we estimated their abundance in two landraces, one with a genome similar in size to that of the maize reference and the other with a 30% larger genome. For all three accessions, we assessed TE abundance as well as 22 nt and 24 nt siRNA content within leaves. The high copy number retroelements are under targeted similarly by siRNAs among accessions, appear to be born of a rapid bust of activity, and may be currently transpositionally dead or limited. In contrast, the lower copy number group of retrolements are targeted more dynamically and have had a long and ongoing history of transposition in the maize genome. PMID:24743518

  5. Isolation and identification of indigenous plant growth promoting rhizobacteria from Himalayan region of Kashmir and their effect on improving growth and nutrient contents of maize (Zea mays L.).

    PubMed

    Zahid, Mahwish; Abbasi, M Kaleem; Hameed, Sohail; Rahim, Nasir

    2015-01-01

    Introduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant-microbes interactions that may affect ecosystems sustainability, agricultural productivity, and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of 100 isolates were isolated from these sites, out of which eight (HJR1, HJR2, HJR3, HJR4, HJR5, MR6, HJR7, HJR8) were selected in vitro for their plant growth promoting ability (PGPA) including phosphorus solubilization, indole-3-acetic acid (IAA) production and N2 fixation. The 16S rRNA gene sequencing technique was used for molecular identity and authentication. Isolates were then further tested for their effects on growth and nutrient contents of maize (Z. mays L.) under pouch and pot conditions. The 16S rRNA gene sequencing and phylogenetic analysis identified these isolates belong to Pseudomonas and Bacillus genera. The isolates promoted plant growth by solubilizing soil P which ranged between 19.2 and 35.6 μg mL(-1). The isolates HJR1, HJR2, HJR3, and HJR5 showed positive activity in acetylene reduction assay showing their N2-fixation potential. All eight isolates showed the potential to produce IAA in the range of 0.9-5.39 μg mL(-1) and promote plant growth. Results from a subsequent pot experiment indicated PGPRs distinctly increased maize shoot and root length, shoot and root dry weight, root surface area, leaf surface area, shoot and root N and P contents. Among the eight isolates, HR3 showed a marked P-solubilizing activity, plant growth-promoting attributes, and the potential to be developed as a biofertilizers for integrated nutrient management strategies. PMID:25852667

  6. Antioxidative free and bound phenolic constituents in botanical fractions of Indian specialty maize (Zea mays L.) genotypes.

    PubMed

    Das, Amit K; Singh, Vasudeva

    2016-06-15

    Specialty maize genotypes viz. QPM (quality protein maize), Baby corn, Popcorn and Sweet corn, which are usually consumed in whole forms can be good supplements of phenolic antioxidants. Botanical fractions of these maize genotypes were analyzed to explore the distribution of free and bound phenolics. HPLC and ESI-MS/MS results indicated the presence of vanillic, syringic, p-hydroxybenzoic, caffeic, p-coumaric, ferulic and isoferulic acids along with cyanidin-3-O-glucoside, kaempferol and quercetin. Germs of maize samples contained significantly higher free phenolics than pericarps, whereas, pericarps contained 74-83% of bound ones. QPM and Popcorn contained only 3% free phenolics whereas, Baby corn and Sweet corn had 14-17%. Unlike in peroxide scavenging and reducing capacity, anti-radical capacity of free phenolics of germs was significantly higher than that of pericarps. Free phenolics contributed 0.2-1.65%, 2-5% and 42-49% in anti-radical, peroxide scavenging and reducing capacity, respectively. Among lipophilic tocochromanols γ-tocopherol was the most abundant isomer in the samples among which Sweet corn contained the most (84.2 μg/g). Data showed that specialty maize genotypes are rich sources of hydrophilic and lipophilic bioactives and are natural antioxidants. PMID:26868580

  7. Unraveling the genetic architecture of subtropical maize (Zea mays L.) lines to assess their utility in breeding programs

    PubMed Central

    2013-01-01

    Background Maize is an increasingly important food crop in southeast Asia. The elucidation of its genetic architecture, accomplished by exploring quantitative trait loci and useful alleles in various lines across numerous breeding programs, is therefore of great interest. The present study aimed to characterize subtropical maize lines using high-quality SNPs distributed throughout the genome. Results We genotyped a panel of 240 subtropical elite maize inbred lines and carried out linkage disequilibrium, genetic diversity, population structure, and principal component analyses on the generated SNP data. The mean SNP distance across the genome was 70 Kb. The genome had both high and low linkage disequilibrium (LD) regions; the latter were dominant in areas near the gene-rich telomeric portions where recombination is frequent. A total of 252 haplotype blocks, ranging in size from 1 to 15.8 Mb, were identified. Slow LD decay (200–300 Kb) at r 2  ≤ 0.1 across all chromosomes explained the selection of favorable traits around low LD regions in different breeding programs. The association mapping panel was characterized by strong population substructure. Genotypes were grouped into three distinct clusters with a mean genetic dissimilarity coefficient of 0.36. Conclusions The genotyped panel of subtropical maize lines characterized in this study should be useful for association mapping of agronomically important genes. The dissimilarity uncovered among genotypes provides an opportunity to exploit the heterotic potential of subtropical elite maize breeding lines. PMID:24330649

  8. The mechanisms of low nitrogen induced weakened photosynthesis in summer maize (Zea mays L.) under field conditions.

    PubMed

    Wei, Shanshan; Wang, Xiangyu; Shi, Deyang; Li, Yanhong; Zhang, Jiwang; Liu, Peng; Zhao, Bin; Dong, Shuting

    2016-08-01

    Soil nitrogen (N) shortage is a problem which affects many developing nations. Crops grown with low soil N levels show a marked decrease in the rate of photosynthesis and this deficiency reduces crop yield significantly. Therefore, developing a better understanding of the mechanisms by which low N levels cause decreased photosynthesis is crucial for maize agriculture. To better understand this process, we assessed the responses of photosynthesis traits and enzymatic activities in the summer maize cultivar Denghai 618 under field conditions with and without the use of N fertilisers. We measured photosynthesis parameters, and compared proteome compositions to identify the mechanisms of physiological and biochemical adaptations to N deficiency in maize. We observed that parameters that indicated the rate of photosynthesis decreased significantly under N deficiency, and this response was associated with leaf senescence. Moreover, we identified 37 proteins involved in leaf photosynthesis, and found that N deficiency significantly affected light-dependent and light-independent reactions in maize leaf photosynthesis. Although further analysis is required to fully elucidate the roles of these proteins in the response to N deficiency, our study identified candidate proteins which may be involved in the regulatory mechanisms involved in reduced photosynthesis under low N conditions in maize. PMID:27101123

  9. Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population

    PubMed Central

    Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

    2015-01-01

    Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize. PMID:26509792

  10. Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population.

    PubMed

    Ding, Junqiang; Zhang, Luyan; Chen, Jiafa; Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

    2015-01-01

    Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize. PMID:26509792

  11. The response of maize (Zea mays L.) plant assisted with bacterial consortium and fertilizer under oily sludge.

    PubMed

    Shahzad, Asim; Saddiqui, Samina; Bano, Asghari

    2016-01-01

    The objective of this study was to evaluate the role of PGPR consortium and fertilizer alone and in combination on the physiology of maize grown under oily sludge stress environment as well on the soil nutrient status. Consortium was prepared from Bacillus cereus (Acc KR232400), Bacillus altitudinis (Acc KF859970), Comamonas (Delftia) belonging to family Comamonadacea (Acc KF859971) and Stenotrophomonasmaltophilia (Acc KF859973). The experiment was conducted in pots with complete randomized design with four replicates and kept in field. Oily sludge was mixed in ml and Ammonium nitrate and Diammonium phosphate (DAP) were added at 70 ug/g and 7 ug/g at sowing. The plant was harvested at 21 d for estimation of protein, proline and antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD). To study the degradation, total petroleum hydrocarbon was extracted by soxhelt extraction and extract was analyzed by GC-FID at different period after incubation. Combined application of consortium and fertilizer enhanced the germination %, protein and, proline content by 90,130 and 99% higher than untreated maize plants. Bioavailability of macro and micro nutrient was also enhanced with consortium and fertilizer in oily sludge. The consortium and fertilizer in combined treatment decreased the superoxide dismutase (SOD), peroxidase dismutase (POD) of the maize leaves grown in oily sludge. Degradation of total petroleum hydrocarbon (TPHs) was 59% higher in combined application of consortium and fertilizer than untreated maize at 3 d. The bacterial consortium can enhanced the maize tolerance to oily sludge and enhanced degradation of total petroleum hydrocarbon (TPHs). The maize can be considered as tolerant plant species to remediate oily sludge contaminated soils. PMID:26587972

  12. Registration of temperate quality protein maize (QPM) lines BQPM9, BQPM10, BQPM11, BQPM12, BQPM13, BQPM14, BQPM15, BQPM16, and BQPM17

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The discovery of the opaque2 (o2) mutation and o2 modifier genes in maize (Zea mays L.) has resulted in the development of Quality Protein Maize (QPM) lines with higher lysine and tryptophan content. QPM lines BQPM9, BQPM10, BQPM11, BQPM12, BQPM13, BQPM14, BQPM15, BQPM16, and BQPM17 were developed a...

  13. β-Cryptoxanthin biofortified maize (Zea mays) increases β-cryptoxanthin concentration and enhances the color of chicken egg yolk.

    PubMed

    Liu, Y-Q; Davis, C R; Schmaelzle, S T; Rocheford, T; Cook, M E; Tanumihardjo, S A

    2012-02-01

    The laying hen has a natural ability to deposit carotenoids into its egg yolks, especially the xanthophyll carotenoid lutein that is used commercially as an egg colorant. Can this ability to deposit carotenoids be used to enrich egg yolk provitamin A value? After a 10-d carotenoid depletion period in hens (n = 24), the effects of a 20-d intervention with high-β-cryptoxanthin, high-β-carotene, or typical yellow maize on color and carotenoid profile were compared with the effects of a white maize diet (n = 6/treatment). Eggs were collected every other day and yolks were analyzed by using a portable colorimeter to define the color space and by using an HPLC to determine the carotenoid profile. The high-β-cryptoxanthin and yellow maize increased β-cryptoxanthin in the yolk (0.55 ± 0.08 to 4.20 ± 0.56 nmol/g and 0.55 ± 0.08 to 1.06 ± 0.12 nmol/g, respectively; P < 0.001). Provitamin A equivalents increased in eggs from hens fed high-β-cryptoxanthin maize (P < 0.001) but not the high-β-carotene maize. The color (L*, a*, and b*) assessment of the yolks showed an increase in the high-β-cryptoxanthin treatment for the red-green a* scale (P < 0.001) and a decrease for the light-dark L* scale (P < 0.001). No appreciable change was noted in the yellow-blue b* scale for the high-β-cryptoxanthin treatment; but significant changes were noted for the yellow (P = 0.002) and high-β-carotene maize (P = 0.005) treatments, which were most evident at the end of the washout period with white maize. β-Cryptoxanthin-biofortified maize is a potential vehicle to elevate provitamin A equivalents and to enhance the color of yolks. This could lead to a human health benefit if widely adopted. PMID:22252357

  14. 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

  15. Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L.) Planted under Early and Optimum Sowing Conditions

    PubMed Central

    Bakhtavar, Muhammad Amir; Afzal, Irfan; Basra, Shahzad Maqsood Ahmed; Ahmad, Azraf-ul-Haq; Noor, Mehmood Ali

    2015-01-01

    Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage) and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET), improved emergence index (EI) and final emergence percentage (FEP). Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes. PMID:25928295

  16. X1-homologous genes family as central components in biotic and abiotic stresses response in maize (Zea mays L.).

    PubMed

    Zhang, Zhongbao; Chen, Yajuan; Zhao, Dan; Li, Ruifen; Wang, Hongzhi; Zhang, Jiewei; Wei, Jianhua

    2014-03-01

    X1-homologous genes (XHS) encode plant specific proteins containing three basic domains (XH, XS, zf-XS). In spite of their physiological importance, systematic analyses of ZmXHS genes have not yet been explored. In this study, we isolated and characterized ten ZmXHS genes in a whole-of-genome analysis of the maize genome. A total of ten members of this family were identified in maize genome. The ten ZmXHS genes were distributed on seven maize chromosomes. Multiple alignment and motif display results revealed that most ZmXHS proteins share all the three conserved domains. Putative cis-elements involved in abiotic stress responsive, phytohormone, pollen-specific and quantitative, seed development and germination, light and circadian rhythms regulation, Ca(2+)-responsive, root hair cell-specific, and CO(2)-responsive transcriptional activation were observed in the promoters of ZmXHS genes. Yeast hybrid assay revealed that the XH domain of ZmXHS5 was necessary for interaction with itself and ZmXHS2. Microarray data showed that the ZmXHS genes had tissue-specific expression patterns in the maize developmental steps and biotic stresses response. Quantitative real-time PCR analysis results indicated that, except ZmXHS9, the other nine ZmXHS genes were induced in the seedling leaves by at least one of the four abiotic stresses applied. PMID:24676795

  17. An 11-bp insertion in Zea mays FatB reduces the palmitate content of fatty acids in maize grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acids in maize kernels are important for human and livestock health. We combined linkage and association analysis to fine-map the major QTL-Pal9 to a 90-kb region, in which only one candidate gene was identified. The gene was named ZmFatB and is orthologous to FatB in Arabidopsis, with a simil...

  18. Potential anthranilate modifying enzymes of maize mutant bf-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedlings of maize mutant bf-1 exhibit blue fluorescence and a distinct grape odor due to an accumulation of methyl anthranilate and other anthranilate related compounds. The bf-1 also expresses a feedback insensitive anthranilate synthase. Previously, we identified a unique mutation in anthranila...

  19. Histological and transcript analyses of intact somatic embryos in an elite maize (Zea mays L.) inbred line Y423.

    PubMed

    Liu, Beibei; Su, Shengzhong; Wu, Ying; Li, Ying; Shan, Xiaohui; Li, Shipeng; Liu, Hongkui; Dong, Haixiao; Ding, Meiqi; Han, Junyou; Yuan, Yaping

    2015-07-01

    Intact somatic embryos were obtained from an elite maize inbred line Y423, bred in our laboratory. Using 13-day immature embryos after self-pollination as explants, and after 4-5 times subculture, a large number of somatic embryos were detected on the surface of the embryonic calli on the medium. The intact somatic embryos were transferred into the differential medium, where the plantlets regenerated with shoots and roots forming simultaneously. Histological analysis and scanning electron micrographs confirmed the different developmental stages of somatic embryogenesis, including globular-shaped embryo, pear-shaped embryo, scutiform embryo, and mature embryo. cDNA-amplified fragment length polymorphism (cDNA-AFLP) was used for comparative transcript profiling between embryogenic and non-embryogenic calli of a new elite maize inbred line Y423 during somatic embryogenesis. Differentially expressed genes were cloned and sequenced. Gene Ontology analysis of 117 candidate genes indicated their involvement in cellular component, biological process and molecular function. Nine of the candidate genes were selected. The changes in their expression levels during embryo induction and regeneration were analyzed in detail using quantitative real-time PCR. Two full-length cDNA sequences, encoding ZmSUF4 (suppressor of fir 4-like protein) and ZmDRP3A (dynamin-related protein), were cloned successfully from intact somatic embryos of the elite inbred maize line Y423. Here, a procedure for maize plant regeneration from somatic embryos is described. Additionally, the possible roles of some of these genes during the somatic embryogenesis has been discussed. This study is a systematic analysis of the cellular and molecular mechanism during the formation of intact somatic embryos in maize. PMID:25931320

  20. Respiration of sugars in spinach (Spinacia oleraces), maize (Zea mays), and Chlamydomonas reinhardtii F-60 chloroplasts with emphasis on the hexose kinases

    SciTech Connect

    Singh, K.K.; Chen, C.; Epstein, D.K.; Gibbs, M. )

    1993-06-01

    The role of hexokinase in carbohydrate degradation in isolated, intact chloroplasts was evaluated. This was accomplished by monitoring the evolution of [sup 14]CO[sub 2] from darkened spinach (Spinacia oleracea), maize (Zea mays) mesophyll, and Chlamydomonas reinhardtii chloroplasts externally supplied with [sup 14]C-labeled fructose, glucose, mannose, galactose, maltose, and ribose. Glucose and ribose were the preferred substrates with the Chlamydomonas and maize chloroplasts, respectively. The rate of CO[sub 2] release from fructose was about twice that from glucose in the spinach chloroplast. externally supplied ATP stimulated the rate of CO[sub 2] release. The pH optimum for CO[sub 2] release was 7.5 with ribose and fructose and 8.5 with glucose as substrates. Probing the outer membrane polypeptides of the intact spinach chloroplast with two proteases, trypsin and thermolysin, decreased [sup 14]CO[sub 2] release from glucose about 50% but had little effect when fructose was the substrate. Tryptic digestion decreased CO[sub 2] release from glucose in the Chlamydomonas chloroplast about 70%. [sup 14]CO[sub 2] evolution from [1-[sup 14]C]-glucose-6-phosphate in both chloroplasts was unaffected by treatment with trypsin. Enzymic analysis of the supernatant (stroma) of the lysed spinach chloroplast indicated a hexokinase active primarily with fructose but with some affinity for glucose. The pellet (membranal fraction) contained a hexokinase utilizing both glucose and fructose but with considerably less total activity than the stormal enzyme. Treatment with trypsin and thermolysin eliminated more than 50% of the glucokinase activity but had little effect on fructokinase activity in the spinach chloroplast. Tryptic digestion of the Chlamydomonas chloroplast resulted in a loss of about 90% of glucokinase activity. 34 refs., 2 figs., 6 tabs.

  1. Contrasting effects of biochar, compost and farm manure on alleviation of nickel toxicity in maize (Zea mays L.) in relation to plant growth, photosynthesis and metal uptake.

    PubMed

    Rehman, Muhammad Zia-Ur; Rizwan, Muhammad; Ali, Shafaqat; Fatima, Nida; Yousaf, Balal; Naeem, Asif; Sabir, Muhammad; Ahmad, Hamaad Raza; Ok, Yong Sik

    2016-11-01

    Nickel (Ni) toxicity in agricultural crops is a widespread problem while little is known about the role of biochar (BC) and other organic amendments like farm manure (FM) from cattle farm and compost (Cmp) on its alleviation. A greenhouse experiment was conducted to evaluate the effects of BC, Cmp and FM on physiological and biochemical characteristics of maize (Zea mays L.) under Ni stress. Maize was grown in Ni spiked soil without and with two rates of the amendments (equivalent to 1% and 2% organic carbon, OC) applied separately to the soil. After harvest, plant height, root length, dry weight, chlorophyll contents, gas exchange characteristics and trace elements in plants were determined. In addition, post-harvest soil characteristics like pHs, ECe and bioavailable Ni were also determined. Compared to the control, all of the amendments increased plant height, root length, shoot and root dry weight with the maximum increase in all parameters by FM (2% OC) treatment. Similarly, total chlorophyll contents and gas exchange characteristics significantly increased with the application of amendments being maximum with FM (2% OC) application. Amendments significantly increased copper, zinc, manganese and iron concentrations and decreased Ni concentrations in the plants. The highest reduction in shoot Ni concentration was recorded with FM (2% OC) followed by BC (2% OC) being 73.2% and 61.1% lower compared to the control, respectively. The maximum increase in soil pH and decrease in AB-DTPA extractable Ni was recorded with BC (2% OC) followed by FM (2% OC). It is concluded that FM (2% OC) was the most effective in reducing Ni toxicity to plants by reducing Ni uptake while BC (2% OC) was the most effective in decreasing bioavailable Ni in the soil through increasing soil pH. However, long-term field studies are needed to evaluate the effects of these amendments in reducing Ni toxicity in plants. PMID:27467022

  2. Identification of B6T173 (ZmPrx35) as the prevailing peroxidase in highly insect-resistant maize (Zea mays, p84C3) kernels by activity-directed purification

    PubMed Central

    López-Castillo, Laura M.; López-Arciniega, Janet A. I.; Guerrero-Rangel, Armando; Valdés-Rodríguez, Silvia; Brieba, Luis G.; García-Lara, Silverio; Winkler, Robert

    2015-01-01

    Plant peroxidases (PODs) are involved in diverse physiological processes, including defense against pathogens and insects. Contrary to their biological importance, only very few plant PODs have been proven on protein level, because their low abundance makes them difficult to detect in standard proteomics work-flows. A statistically significant positive correlation between POD activity and post-harvest insect resistance has been found for maize (Zea mays, p84C3) kernels. In combining activity-directed protein purification, genomic and proteomic tools we found that protein B6T173 (ZmPrx35) is responsible for the majority of the POD activity of the kernel. We successfully produced recombinant ZmPrx35 protein in Escherichia coli and demonstrate both, in vitro activity and the presence of a haem (heme) cofactor of the enzyme. Our findings support the screening for insect resistant maize variants and the construction of genetically optimized maize plants. PMID:26379694

  3. Expression and functional analysis of genes encoding cytokinin receptor-like histidine kinase in maize (Zea mays L.).

    PubMed

    Wang, Bo; Chen, Yanhong; Guo, Baojian; Kabir, Muhammad Rezaul; Yao, Yingyin; Peng, Huiru; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu

    2014-08-01

    Cytokinin signaling is vital for plant growth and development which function via the two-component system (TCS). As one of the key component of TCS, transmembrane histidine kinases (HK) are encoded by a small gene family in plants. In this study, we focused on expression and functional analysis of cytokinin receptor-like HK genes (ZmHK) in maize. Firstly, bioinformatics analysis revealed that seven cloned ZmHK genes have different expression patterns during maize development. Secondly, ectopic expression by CaMV35S promoter in Arabidopsis further revealed that functional differentiation exists among these seven members. Among them, the ZmHK1a2-OX transgenic line has the lowest germination rate in the dark, ZmHK1-OX and ZmHK2a2-OX can delay leaf senescence, and seed size of ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX was obviously reduced as compared to wild type. Additionally, ZmHK genes play opposite roles in shoot and root development; all ZmHK-OX transgenic lines display obvious shorter root length and reduced number of lateral roots, but enhanced shoot development compared with the wild type. Most notably, Arabidopsis response regulator ARR5 gene was up-regulated in ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX as compared to wild type. Although the causal link between ZmHK genes and cytokinin signaling pathway is still an area to be further elucidated, these findings reflected that the diversification of ZmHK genes expression patterns and functions occurred in the course of maize evolution, indicating that some ZmHK genes might play different roles during maize development. PMID:24585212

  4. Characterization of AMT-mediated high-affinity ammonium uptake in roots of maize (Zea mays L.).

    PubMed

    Gu, Riliang; Duan, Fengying; An, Xia; Zhang, Fusuo; von Wirén, Nicolaus; Yuan, Lixing

    2013-09-01

    High-affinity ammonium uptake in plant roots is mainly mediated by AMT1-type ammonium transporters, and their regulation varies depending on the plant species. In this study we aimed at characterizing AMT-mediated ammonium transport in maize, for which ammonium-based fertilizer is an important nitrogen (N) source. Two ammonium transporter genes, ZmAMT1;1a and ZmAMT1;3, were isolated from a maize root-specific cDNA library by functional complementation of an ammonium uptake-defective yeast mutant. Ectopic expression of both genes in an ammonium uptake-defective Arabidopsis mutant conferred high-affinity ammonium uptake capacities in roots with substrate affinities of 48 and 33 μM for ZmAMT1;1a and ZmAMT1;3, respectively. In situ hybridization revealed co-localization of both ZmAMT genes on the rhizodermis, suggesting an involvement in capturing ammonium from the rhizosphere. In N-deficient maize roots, influx increased significantly while ZmAMT expression did not. Ammonium resupply to N-deficient or nitrate-pre-cultured roots, however, rapidly enhanced both influx and ZmAMT transcript levels, revealing a substrate-inducible regulation of ammonium uptake. In conclusion, the two rhizodermis-localized transporters ZmAMT1;1a and ZmAMT1;3 are most probably the major components in the high-affinity transport system in maize roots. A particular regulatory feature is their persistent induction by ammonium rather than an up-regulation under N deficiency. PMID:23832511

  5. Antioxidant capacity and antimutagenic activity of anthocyanin and carotenoid extracts from nixtamalized pigmented Creole maize races (Zea mays L.).

    PubMed

    Mendoza-Díaz, Sandra; Ortiz-Valerio, Ma del Carmen; Castaño-Tostado, Eduardo; Figueroa-Cárdenas, Juan de Dios; Reynoso-Camacho, Rosalía; Ramos-Gómez, Minerva; Campos-Vega, Rocio; Loarca-Piña, Guadalupe

    2012-12-01

    Nixtamalization process is the first step to obtain maize based products, like tortillas; however, in both the traditional and commercial processes, white grain is generally preferred. Creole maize races, mainly pigmented varieties, have increasingly attention since these are rich in anthocyanins and carotenoids. The aim of this investigation was to evaluate the antioxidant and antimutagenic activity of rich anthocyanins and carotenoids extracts from creole maize races before (grain) and after (masa and tortilla) the nixtamalization process. Most anthocyanins and carotenoids were lost during nixtamalization. Before nixtamalization, blue and red genotypes contained either higher antioxidant capacity and anthocyanin contents (963 ± 10.0 and 212.36 ± 0.36 mg of cyanidin-3-glucoside eq/100 g, respectively) than the white and yellow genotypes. However, the highest carotenoid levels were displayed by red grains (1.01 ± 0.07 to 1.14 ± 0.08 μg of β-carotene eq/g extract). Anthocyanins losses were observed when the blue grains were processed into masa (83 %) and tortillas (64 %). Anthocyanins content correlated with antiradical activity (r = 0.57) and with 2-aminoanthracene -induced mutagenicity inhibition on TA98 and TA100 (r = -0.62 and r = -0.44, respectively). For white grains, nixtamalization also reduced carotenoids (53 to 56 %), but not antioxidant activity and 2-Aa-induced mutagenicity. Throughout the nixtamalization process steps, all the extracts showed antimutagenic activity against 2-aminoanthracene-induced mutagenicity (23 to 90 %), displaying higher potential to inhibit base changes mutations than frameshift mutations in the genome of the tasted microorganism (TA100 and TA98, respectively). The results suggest that even though there were pigment losses, creole maize pigments show antioxidant and antimutagenic activities after nixtamalization process. PMID:23230010

  6. Assessment of average exposure to organochlorine pesticides in southern Togo from water, maize (Zea mays) and cowpea (Vigna unguiculata).

    PubMed

    Mawussi, G; Sanda, K; Merlina, G; Pinelli, E

    2009-03-01

    Drinking water, cowpea and maize grains were sampled in some potentially exposed agro-ecological areas in Togo and analysed for their contamination by some common organochlorine pesticides. A total of 19 organochlorine pesticides were investigated in ten subsamples of maize, ten subsamples of cowpea and nine subsamples of drinking water. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatography-mass spectrometry (GC/MS). Estimated daily intakes (EDIs) of pesticides were also determined. Pesticides residues in drinking water (0.04-0.40 microg l(-1)) were higher than the maximum residue limit (MRL) (0.03 microg l(-1)) set by the World Health Organization (WHO). Dieldrin, endrin, heptachlor epoxide and endosulfan levels (13.16-98.79 microg kg(-1)) in cowpea grains exceeded MRLs applied in France (10-50 microg kg(-1)). Contaminants' levels in maize grains (0.53-65.70 microg kg(-1)) were below the MRLs (20-100 microg kg(-1)) set by the Food and Agriculture Organization (FAO) and the WHO. EDIs of the tested pesticides ranged from 0.02% to 162.07% of the acceptable daily intakes (ADIs). Population exposure levels of dieldrin and heptachlor epoxide were higher than the FAO/WHO standards. A comprehensive national monitoring programme on organochlorine pesticides should be undertaken to include such other relevant sources like meat, fish, eggs and milk. PMID:19680908

  7. Photosynthetic capacity, nutrient status, and growth of maize (Zea mays L.) upon MgSO4 leaf-application

    PubMed Central

    Jezek, Mareike; Geilfus, Christoph-Martin; Bayer, Anne; Mühling, Karl-Hermann

    2015-01-01

    The major plant nutrient magnesium (Mg) is involved in numerous physiological processes and its deficiency can severely reduce the yield and quality of crops. Since Mg availability in soil and uptake into the plant is often limited by unfavorable soil or climatic conditions, application of Mg onto leaves, the site with highest physiological Mg demand, might be a reasonable alternative fertilization strategy. This study aimed to investigate, if MgSO4 leaf-application in practically relevant amounts can efficiently alleviate the effects of Mg starvation in maize, namely reduced photosynthesis capacity, disturbed ion homeostasis and growth depression. Results clearly demonstrated that Mg deficiency could be mitigated by MgSO4 leaf-application as efficiently as by resupply of MgSO4 via the roots in vegetative maize plants. Significant increases in SPAD values and net rate of CO2-assimilation as well as enhanced shoot biomass have been achieved. Ion analysis furthermore revealed an improvement of the nutrient status of Mg-deficient plants with regard to [Mg], [K], and [Mn] in distinct organs, thereby reducing the risk of Mn-toxicity at the rootside, which often occurs together with Mg deficiency on acid soils. In conclusion, foliar fertilization with Mg proved to be an efficient strategy to adequately supply maize plants with Mg and might hence be of practical relevance to correct nutrient deficiencies during the growing season. PMID:25620973

  8. Inventory and general analysis of the ATP-binding cassette (ABC) gene superfamily in maize (Zea mays L.).

    PubMed

    Pang, Kaiyuan; Li, Yanjiao; Liu, Menghan; Meng, Zhaodong; Yu, Yanli

    2013-09-10

    The metabolic functions of ATP-binding cassette (or ABC) proteins, one of the largest families of proteins presented in all organisms, have been investigated in many protozoan, animal and plant species. To facilitate more systematic and complicated studies on maize ABC proteins in the future, we present the first complete inventory of these proteins, including 130 open reading frames (ORFs), and provide general descriptions of their classifications, basic structures, typical functions, evolution track analysis and expression profiles. The 130 ORFs were assigned to eight subfamilies based on their structures and homological features. Five of these subfamilies consist of 109 proteins, containing transmembrane domains (TM) performing as transporters. The rest three subfamilies contain 21 soluble proteins involved in various functions other than molecular transport. A comparison of ABC proteins among nine selected species revealed either convergence or divergence in each of the ABC subfamilies. Generally, plant genomes contain far more ABC genes than animal genomes. The expression profiles and evolution track of each maize ABC gene were further investigated, the results of which could provide clues for analyzing their functions. Quantitative real-time polymerase chain reaction experiments (PCR) were conducted to detect induced expression in select ABC genes under several common stresses. This investigation provides valuable information for future research on stress tolerance in plants and potential strategies for enhancing maize production under stressful conditions. PMID:23747399

  9. Comparative proteomic analysis revealing the complex network associated with waterlogging stress in maize (Zea mays L.) seedling root cells.

    PubMed

    Yu, Feng; Han, Xuesong; Geng, Cunjuan; Zhao, Yanxin; Zhang, Zuxin; Qiu, Fazhan

    2015-01-01

    Soil waterlogging is one of the major abiotic stresses affecting maize grain yields. To understand the molecular mechanisms underlying waterlogging tolerance in maize, the iTRAQ LC-MS/MS technique was employed to map the proteomes of seedling root cells of the A3237 (tolerant inbred) and A3239 (sensitive inbred) lines under control and waterlogging conditions. Among the 3318 proteins identified, 211 were differentially abundant proteins (DAPs), of which 81 were specific to A3237 and 57 were specific to A3239. These DAPs were categorized into 11 groups that were closely related to the plant stress response, including metabolism, energy, transport, and disease/defense. In the waterlogged A3237 root cells, NADP-malic enzyme, glutamate decarboxylase, coproporphyrinogen III oxidase, GSH S-transferase, GSH dehydrogenase, and xyloglucan endotransglycosylase 6 were specifically accumulated to manage energy consumption, maintain pH levels, and minimize oxidative damage. The evaluations of five specific physiological parameters (alcohol dehydrogenase activity and GSH, malondialdehyde, adenosine 5'-triphosphate, and nicotinamide adenine dinucleotide concentrations) were in agreement with the proteomic results. Moreover, based on the proteomic assay, eight representative genes encoding DAPs were selected for validation at the transcriptional level. qRT-PCR revealed that the expression levels of these genes correlated with their observed protein abundance. These findings shed light on the complex mechanisms underlying waterlogging tolerance in maize. All MS data have been deposited into the ProteomeXchange with the identifier PXD001125 http://proteomecentral.proteomexchange.org/dataset/PXD001125. PMID:25316036

  10. Development of combined imbibition and hydrothermal threshold models to simulate maize (Zea mays) and chickpea (Cicer arietinum) seed germination in variable environments.

    PubMed

    Finch-Savage, W E; Rowse, H R; Dent, K C

    2005-03-01

    * The ability of hydrothermal time (HTT) and virtual osmotic potential (VOP) models to describe the kinetics of maize (Zea mays) and chickpea (Cicer arietinum) seed germination under variable conditions of water potential was investigated with a view to gaining an improved understanding of the impact of on-farm seed priming on seedling establishment through simulation. * Germination and/or imbibition time courses were recorded over a wide range of constant temperatures and water potentials and simple stepwise changes in water potential. * Both models adequately described germination under constant environmental conditions, but not conditions of water potential that varied. To test the hypothesis that this inaccuracy resulted from the use of ambient water potential, a parsimonious model of seed imbibition was developed to calibrate the HTT and VOP models (IHTT and IVOP) and drive them with estimates of seed water potential. * The IHTT and IVOP models described germination during stepwise changes in water potential more accurately than the conventional models, and should contribute to improved predictions of germination time in the field. PMID:15720694

  11. Influence of Rhizophagus irregularis inoculation and phosphorus application on growth and arsenic accumulation in maize (Zea mays L.) cultivated on an arsenic-contaminated soil.

    PubMed

    Cattani, I; Beone, G M; Gonnelli, C

    2015-05-01

    Southern Tuscany (Italy) is characterized by extensive arsenic (As) anomalies, with concentrations of up to 2000 mg kg soil(-1). Samples from the location of Scarlino, containing about 200 mg kg(-1) of As, were used to study the influence of the inoculation of an arbuscular mycorrhizal (AM) fungus (Rhizophagus irregularis, previously known as Glomus intraradices) and of phosphorus (P) application, separately and in combination, on As speciation in the rhizosphere of Zea mays on plant growth and As accumulation. Also, P distribution in plant parts was investigated. Each treatment produced a moderate rise of As(III) in the rhizosphere, increased As(III) and lowered As(V) concentration in shoots. P treatment, alone or in combination with AM, augmented the plant biomass. The treatments did not affect total As concentration in the shoots (with all the values <1 mg kg(-1) dry weight), while in the roots it was lowered by P treatment alone. Such decrease was probably a consequence of the competition between P and As(V) for the same transport systems, interestingly nullified by the combination with AM treatment. P concentration was higher with AM only in both shoots and roots. Therefore, the obtained results can be extremely encouraging for maize cultivation on a marginal land, like the one studied. PMID:25716900

  12. Soil water capture trends over 50 years of single-cross maize (Zea mays L.) breeding in the US corn-belt.

    PubMed

    Reyes, Andres; Messina, Carlos D; Hammer, Graeme L; Liu, Lu; van Oosterom, Erik; Lafitte, Renee; Cooper, Mark

    2015-12-01

    Breeders have successfully improved maize (Zea mays L.) grain yield for the conditions of the US corn-belt over the past 80 years, with the past 50 years utilizing single-cross hybrids. Long-term improvement for grain yield under water-limited conditions has also been reported. Grain yield under water-limited conditions depends on water use, water use efficiency, and harvest index. It has been hypothesized that long-term genetic gain for yield could be due, in part, to increased water capture from the soil. This hypothesis was tested using a set of elite single-cross hybrids that were released by DuPont Pioneer between 1963 and 2009. Eighteen hybrids were grown in the field during 2010 and 2011 growing seasons at Woodland, CA, USA. Crops grew predominantly on stored soil water and drought stress increased as the season progressed. Soil water content was measured to 300cm depth throughout the growing season. Significant water extraction occurred to a depth of 240-300cm and seasonal water use was calculated from the change in soil water over this rooting zone. Grain yield increased significantly with year of commercialization, but no such trend was observed for total water extraction. Therefore, the measured genetic gain for yield for the period represented by this set of hybrids must be related to either increased efficiency of water use or increased carbon partitioning to the grain, rather than increased soil water uptake. PMID:26428065

  13. Cell cycle arrest induced by inhibitors of epigenetic modifications in maize (Zea mays) seedling leaves: characterization of the process and possible mechanisms involved.

    PubMed

    Wang, Pu; Zhang, Hao; Hou, Haoli; Wang, Qing; Li, Yingnan; Huang, Yan; Xie, Liangfu; Gao, Fei; He, Shibin; Li, Lijia

    2016-07-01

    Epigenetic modifications play crucial roles in the regulation of chromatin architecture and are involved in cell cycle progression, including mitosis and meiosis. To explore the relationship between epigenetic modifications and the cell cycle, we treated maize (Zea mays) seedlings with six different epigenetic modification-related inhibitors and identified the postsynthetic phase (G2 ) arrest via flow cytometry analysis. Total H4K5ac levels were significantly increased and the distribution of H3S10ph signalling was obviously changed in mitosis under various treatments. Further statistics of the cells in different periods of mitosis confirmed that the cell cycle was arrested at preprophase. Concentrations of hydrogen peroxide were relatively higher in the treated plants and the antioxidant thiourea could negate the influence of the inhibitors. Moreover, all of the treated plants displayed negative results in the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) and γ-H2AX immunostaining assays after exposure for 3 d. Additionally, the expression level of topoisomerase genes in the treated plants was relatively lower than that in the untreated plants. These results suggest that these inhibitors of epigenetic modifications could cause preprophase arrest via reactive oxygen species formation inhibiting the expression of DNA topoisomerase genes, accompanied by changes in the H4K5ac and H3S10ph histone modifications. PMID:27040740

  14. The initiation of lateral roots in the primary roots of maize (Zea mays L.) implies a reactivation of cell proliferation in a group of founder pericycle cells.

    PubMed

    Alarcón, M Victoria; Lloret, Pedro G; Martín-Partido, Gervasio; Salguero, Julio

    2016-03-15

    The initiation of lateral roots (LRs) has generally been viewed as a reactivation of proliferative activity in pericycle cells that are committed to initiate primordia. However, it is also possible that pericycle founder cells that initiate LRs never cease proliferative activity but rather are displaced to the most distal root zones while undertaking successive stages of LR initiation. In this study, we tested these two alternative hypotheses by examining the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into the DNA of meristematic root cells of Zea mays. According to the values for the length of the cell cycle and values for cell displacement along the maize root, our results strongly suggest that pericycle cells that initiate LR primordia ceased proliferative activity upon exiting the meristematic zone. This finding is supported by the existence of a root zone between 4 and 20mm from the root cap junction, in which neither mitotic cells nor labelled nuclei were observed in phloem pericycle cells. PMID:26905196

  15. Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase.

    PubMed

    Nestler, Josefine; Liu, Sanzhen; Wen, Tsui-Jung; Paschold, Anja; Marcon, Caroline; Tang, Ho Man; Li, Delin; Li, Li; Meeley, Robert B; Sakai, Hajime; Bruce, Wesley; Schnable, Patrick S; Hochholdinger, Frank

    2014-09-01

    Root hairs are instrumental for nutrient uptake in monocot cereals. The maize (Zea mays L.) roothairless5 (rth5) mutant displays defects in root hair initiation and elongation manifested by a reduced density and length of root hairs. Map-based cloning revealed that the rth5 gene encodes a monocot-specific NADPH oxidase. RNA-Seq, in situ hybridization and qRT-PCR experiments demonstrated that the rth5 gene displays preferential expression in root hairs but also accumulates to low levels in other tissues. Immunolocalization detected RTH5 proteins in the epidermis of the elongation and differentiation zone of primary roots. Because superoxide and hydrogen peroxide levels are reduced in the tips of growing rth5 mutant root hairs as compared with wild-type, and Reactive oxygen species (ROS) is known to be involved in tip growth, we hypothesize that the RTH5 protein is responsible for establishing the high levels of ROS in the tips of growing root hairs required for elongation. Consistent with this hypothesis, a comparative RNA-Seq analysis of 6-day-old rth5 versus wild-type primary roots revealed significant over-representation of only two gene ontology (GO) classes related to the biological functions (i.e. oxidation/reduction and carbohydrate metabolism) among 893 differentially expressed genes (FDR <5%). Within these two classes the subgroups 'response to oxidative stress' and 'cellulose biosynthesis' were most prominently represented. PMID:24902980

  16. Soil water capture trends over 50 years of single-cross maize (Zea mays L.) breeding in the US corn-belt

    PubMed Central

    Reyes, Andres; Messina, Carlos D.; Hammer, Graeme L.; Liu, Lu; van Oosterom, Erik; Lafitte, Renee; Cooper, Mark

    2015-01-01

    Breeders have successfully improved maize (Zea mays L.) grain yield for the conditions of the US corn-belt over the past 80 years, with the past 50 years utilizing single-cross hybrids. Long-term improvement for grain yield under water-limited conditions has also been reported. Grain yield under water-limited conditions depends on water use, water use efficiency, and harvest index. It has been hypothesized that long-term genetic gain for yield could be due, in part, to increased water capture from the soil. This hypothesis was tested using a set of elite single-cross hybrids that were released by DuPont Pioneer between 1963 and 2009. Eighteen hybrids were grown in the field during 2010 and 2011 growing seasons at Woodland, CA, USA. Crops grew predominantly on stored soil water and drought stress increased as the season progressed. Soil water content was measured to 300cm depth throughout the growing season. Significant water extraction occurred to a depth of 240–300cm and seasonal water use was calculated from the change in soil water over this rooting zone. Grain yield increased significantly with year of commercialization, but no such trend was observed for total water extraction. Therefore, the measured genetic gain for yield for the period represented by this set of hybrids must be related to either increased efficiency of water use or increased carbon partitioning to the grain, rather than increased soil water uptake. PMID:26428065

  17. Simultaneous femtomole determination of cysteine, reduced and oxidized glutathione, and phytochelatin in maize (Zea mays L.) kernels using high-performance liquid chromatography with electrochemical detection.

    PubMed

    Potesil, David; Petrlova, Jitka; Adam, Vojtech; Vacek, Jan; Klejdus, Borivoj; Zehnalek, Josef; Trnkova, Libuse; Havel, Ladislav; Kizek, Rene

    2005-08-19

    Thiol compounds such as cysteine (Cys), reduced (GSH) and oxidized (GSSG) gluathione, and phytochelatins (PCs) play an important role in heavy metal detoxification in plants. These thiols are biological active compounds whose function is elimination of oxidative stress in plant cells. The aim of our work was to optimise sensitive and rapid method of high-performance liquid chromatography coupled with electrochemical detector (HPLC-ED) for determination of the abovementioned thiol compounds in maize (Zea mays L.) kernels. New approach for evaluation of HPLC-ED parameters is described. The most suitable isocratic mobile phase for the separation and detection of Cys, GSH, GSSG and PC2 consisted of methanol (MeOH) and trifluoroacetic acid (TFA). In addition, the influence of concentrations of TFA and ratio of MeOH:TFA on chromatographic separation and detection of the thiol compounds were studied. The mobile phase consisting from methanol and 0.05% (v/v) TFA in ratio 97:3 (%; v/v) was found the most suitable for the thiol compounds determination. Optimal flow rate of the mobile phase was 0.18 ml min(-1) and the column and detector temperature 35 degrees C. Hydrodynamic voltammograms of all studied compounds was obtained due to the selection of the most effective working electrodes potentials. Two most effective detection potentials were selected: 780 mV for the GSSG and PC2 and 680 mV for determination of Cys and GSH. The optimised HPLC-ED method was capable to determine femtomole levels of studied compounds. The detection limits (3 S/N) of the studied thiol compounds were for cysteine 112.8 fmol, GSH 63.5 fmol, GSSG 112.2 fmol and PC2 2.53 pmol per injection (5 microl). The optimised HPLC-ED method was applied to study of the influence of different cadmium concentrations (0, 10 and 100 microM Cd) on content of Cys, GSH, GSSG and PC2 in maize kernels. According to the increasing time of Cd treatment, content of GSH, GSSG and PC2 in maize kernels increased but content

  18. Modification of recombinant maize ChitA chitinase by fungal chitinase-modifying proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In commercial maize, there are at least two different alleles of the chiA gene that encode alloforms of ChitA chitinase, a protein that is abundant in developing seed. Both known alloforms are modified by Bz-cmp, a protein secreted by the fungal pathogen Bipolaris zeicola. One alloform (ChitA-B73) i...

  19. QTL mapping of agronomic waterlogging tolerance using recombinant inbred lines derived from tropical maize (Zea mays L) germplasm.

    PubMed

    Zaidi, Pervez Haider; Rashid, Zerka; Vinayan, Madhumal Thayil; Almeida, Gustavo Dias; Phagna, Ramesh Kumar; Babu, Raman

    2015-01-01

    Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate

  20. QTL Mapping of Agronomic Waterlogging Tolerance Using Recombinant Inbred Lines Derived from Tropical Maize (Zea mays L) Germplasm

    PubMed Central

    Zaidi, Pervez Haider; Rashid, Zerka; Vinayan, Madhumal Thayil; Almeida, Gustavo Dias; Phagna, Ramesh Kumar; Babu, Raman

    2015-01-01

    Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate

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

    PubMed

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

    2015-01-01

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

  2. Phytic acid prevents oxidative stress in seeds: evidence from a maize (Zea mays L.) low phytic acid mutant.

    PubMed

    Doria, Enrico; Galleschi, Luciano; Calucci, Lucia; Pinzino, Calogero; Pilu, Roberto; Cassani, Elena; Nielsen, Erik

    2009-01-01

    A maize mutant defective in the synthesis of phytic acid during seed maturation was used as a tool to study the consequences of the lack of this important reserve substance on seed survival. Data on germinability, free iron level, free radical relative abundance, protein carbonylation level, damage to DNA, degree of lipid peroxidation, alpha- and gamma-tocopherol amount and antioxidant capacity were recorded on seeds of maize B73 and of an isogenic low phytic acid mutant (lpa1-241), either unaged or incubated for 7 d in accelerated ageing conditions (46 degrees C and 100% relative humidity). The lpa1-241 mutant, compared to wild type (wt), showed a lower germination capacity, which decreased further after accelerated ageing. Whole lpa1-241 mutant kernels contained about 50% more free or weakly bound iron than wt ones and showed a higher content of free radicals, mainly concentrated in embryos; in addition, upon accelerated ageing, lpa1-241 seed proteins were more carbonylated and DNA was more damaged, whereas lipids did not appear to be more peroxidated, but the gamma-tocopherol content was decreased by about 50%. These findings can be interpreted in terms of previously reported but never proven antioxidant activity of phytic acid through iron complexation. Therefore, a novel role in plant seed physiology can be assigned to phytic acid, that is, protection against oxidative stress during the seed's life span. As in maize kernels the greater part of phytic acid (and thus of metal ions) is concentrated in the embryo, its antioxidant action may be of particular relevance in this crop. PMID:19204030

  3. Genetic Effects Conferring Heat Tolerance in a Cross of Tolerant × Susceptible Maize (Zea mays L.) Genotypes.

    PubMed

    Naveed, Muhammad; Ahsan, Muhammad; Akram, Hafiz M; Aslam, Muhammad; Ahmed, Nisar

    2016-01-01

    Incessant rise in ambient temperature is threatening sustainability of maize productions, worldwide. Breeding heat resilient synthetics/hybrids is the most economical tool while lack of knowledge of gene action controlling heat and yield relevant traits in maize is hampering progress in this regard. The current study, therefore, was conducted using analyses of generation mean and variance, and narrow sense heritability ([Formula: see text]) and genetic advance as percent of mean (GAM%). Initially, one hundred inbred lines were evaluated for cell membrane thermo-stability and grain yield per plant on mean day/night temperatures of 36.6°C/22.1°C in non-stressed (NS) and 42.7°C/25.7°C in heat-stressed (HS) conditions. From these, one tolerant (ZL-11271) and one susceptible (R-2304-2) genotypes were crossed to develop six basic generations, being evaluated on mean day/night temperatures of 36.1°C/22.8°C (NS) and 42.3°C/25.9°C (HS) in factorial randomized complete block design with three replications. Non-allelic additive-dominance genetic effects were recorded for most traits in both conditions except transpiration rate, being controlled by additive epistatic effects in NS regime. Dissection of genetic variance into additive (D), dominance (H), environment (E) and interaction (F) components revealed significance of only DE variances in HS condition than DE, DFE and DHE variances in NS regime which hinted at the potential role of environments in breeding maize for high temperature tolerance. Additive variance was high for majority of traits in both environments except ear length in NS condition where dominance was at large. Higher magnitudes of [Formula: see text] [Formula: see text] and GAM% for cell membrane thermo-stability, transpiration rate, leaf firing, ear length, kernels per ear and grain yield per plant in both regimes implied that simple selections might be sufficient for further improvement of these traits. Low-to-moderate GAM% for leaf temperature

  4. Genetic Effects Conferring Heat Tolerance in a Cross of Tolerant × Susceptible Maize (Zea mays L.) Genotypes

    PubMed Central

    Naveed, Muhammad; Ahsan, Muhammad; Akram, Hafiz M.; Aslam, Muhammad; Ahmed, Nisar

    2016-01-01

    Incessant rise in ambient temperature is threatening sustainability of maize productions, worldwide. Breeding heat resilient synthetics/hybrids is the most economical tool while lack of knowledge of gene action controlling heat and yield relevant traits in maize is hampering progress in this regard. The current study, therefore, was conducted using analyses of generation mean and variance, and narrow sense heritability (hn2) and genetic advance as percent of mean (GAM%). Initially, one hundred inbred lines were evaluated for cell membrane thermo-stability and grain yield per plant on mean day/night temperatures of 36.6°C/22.1°C in non-stressed (NS) and 42.7°C/25.7°C in heat-stressed (HS) conditions. From these, one tolerant (ZL-11271) and one susceptible (R-2304-2) genotypes were crossed to develop six basic generations, being evaluated on mean day/night temperatures of 36.1°C/22.8°C (NS) and 42.3°C/25.9°C (HS) in factorial randomized complete block design with three replications. Non-allelic additive-dominance genetic effects were recorded for most traits in both conditions except transpiration rate, being controlled by additive epistatic effects in NS regime. Dissection of genetic variance into additive (D), dominance (H), environment (E) and interaction (F) components revealed significance of only DE variances in HS condition than DE, DFE and DHE variances in NS regime which hinted at the potential role of environments in breeding maize for high temperature tolerance. Additive variance was high for majority of traits in both environments except ear length in NS condition where dominance was at large. Higher magnitudes of σD,2 hn2 and GAM% for cell membrane thermo-stability, transpiration rate, leaf firing, ear length, kernels per ear and grain yield per plant in both regimes implied that simple selections might be sufficient for further improvement of these traits. Low-to-moderate GAM% for leaf temperature and 100-grain weight in both conditions

  5. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.

    PubMed

    Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends. PMID:24491720

  6. A new PCR-CGE (size and color) method for simultaneous detection of genetically modified maize events.

    PubMed

    Nadal, Anna; Coll, Anna; La Paz, Jose-Luis; Esteve, Teresa; Pla, Maria

    2006-10-01

    We present a novel multiplex PCR assay for simultaneous detection of multiple transgenic events in maize. Initially, five PCR primers pairs specific to events Bt11, GA21, MON810, and NK603, and Zea mays L. (alcohol dehydrogenase) were included. The event specificity was based on amplification of transgene/plant genome flanking regions, i.e., the same targets as for validated real-time PCR assays. These short and similarly sized amplicons were selected to achieve high and similar amplification efficiency for all targets; however, its unambiguous identification was a technical challenge. We achieved a clear distinction by a novel CGE approach that combined the identification by size and color (CGE-SC). In one single step, all five targets were amplified and specifically labeled with three different fluorescent dyes. The assay was specific and displayed an LOD of 0.1% of each genetically modified organism (GMO). Therefore, it was adequate to fulfill legal thresholds established, e.g., in the European Union. Our CGE-SC based strategy in combination with an adequate labeling design has the potential to simultaneously detect higher numbers of targets. As an example, we present the detection of up to eight targets in a single run. Multiplex PCR-CGE-SC only requires a conventional sequencer device and enables automation and high throughput. In addition, it proved to be transferable to a different laboratory. The number of authorized GMO events is rapidly growing; and the acreage of genetically modified (GM) varieties cultivated and commercialized worldwide is rapidly increasing. In this context, our multiplex PCR-CGE-SC can be suitable for screening GM contents in food. PMID:16972302

  7. Genetic analysis of fumonisin production and virulence of Gibberella fujikuroi mating population A (Fusarium moniliforme) on maize (Zea mays) seedlings.

    PubMed Central

    Desjardins, A E; Plattner, R D; Nelsen, T C; Leslie, J F

    1995-01-01

    The phytopathogenic fungus Gibberella fujikuroi mating population A (anamorph, Fusarium moniliforme) produces fumonisins, which are toxic to a wide range of plant and animal species. Previous studies of field strains have identified a genetic locus, designated fum1, that can determine whether fumonisins are produced. To test the relationship between fumonisin production and virulence on maize seedlings, a cross between a fum1+ field strain that had a high degree of virulence and a fum1- field strain that had a low degree of virulence was made, and ascospore progeny were scored for these traits. Although a range of virulence levels was recovered among the progeny, high levels of virulence were associated with production of fumonisins, and highly virulent, fumonisin-nonproducing progeny were not obtained. A survey of field strains did identify a rare fumonisin-nonproducing strain that was quite high in virulence. Also, the addition of purified fumonisin B1 to virulence assays did not replicate all of the seedling blight symptoms obtained with autoclaved culture material containing fumonisin. These results support the hypothesis that fumonisin plays a role in virulence but also indicate that fumonisin production is not necessary or sufficient for virulence on maize seedlings. PMID:7887628

  8. Molecular cloning, characterization and differential expression of novel phytocystatin gene during tropospheric ozone stress in maize (Zea mays) leaves.

    PubMed

    Ahmad, Rafiq; Zuily-Fodil, Yasmine; Passaquet, Chantal; Ali Khan, Sabaz; Repellin, Anne

    2015-03-01

    In this study, a full-length cDNA encoding a novel phytocystatin gene, designated CC14, was identified in maize leaves. The CC14 gene sequence reported in this study has been deposited in the GenBank database (accession number JF290478). The CC14 gene was cloned into an expression vector pET30 EK/LIC and was then transformed into Escherichia coli strain BL21 (DE3) pLysS to produce a recombinant CC14 protein. The recombinant protein was purified by nickel nitrilotriacetic acid affinity chromatography after induction with 1 mM IPTG. The purified CC14 protein was electrophoresed on SDS-PAGE and a protein 25 kDa in size was observed. Antiprotease activities of the purified recombinant CC14 protein against cysteine proteases and commercially available papain were tested. The results showed that CC14 purified protein suppressed 100% activity of papain and 57-86% plant cysteine protease activity. Moreover, an upregulation of CC14 gene expression was observed after 20 days of ozone stress in maize leaves. Together, these observations concurred to conclude that CC14 gene could potentially be used as a basis for the development of transgenic crops and natural pesticides that resist biotic and abiotic stresses. PMID:25613048

  9. The effect of Piriformospora indica on the root development of maize (Zea mays L.) and remediation of petroleum contaminated soil.

    PubMed

    Zamani, Javad; Hajabbasi, Mohammad Ali; Alaie, Ebrahim; Sepehri, Mozhgan; Leuchtmann, Adrian; Schulin, Rainer

    2016-01-01

    As the depth of soil petroleum contamination can vary substantially under field conditions, a rhizotron experiment was performed to investigate the influence of endophyte, P. indica, on maize growth and degradation of petroleum components in a shallow and a deep-reaching subsurface layer of a soil. For control, a treatment without soil contamination was also included. The degree in contamination and the depth to which it extended had a strong effect on the growth of the plant roots. Contaminated soil layers severely inhibited root growth thus many roots preferred to bypass the shallow contaminated layer and grow in the uncontaminated soil. While the length and branching pattern of these roots were similar to those of uncontaminated treatment. Inoculation of maize with P. indica could improve root distribution and root and shoot growth in all three contamination treatments. This inoculation also enhanced petroleum degradation in soil, especially in the treatment with deep-reaching contamination, consequently the accumulation of petroleum hydrocarbons (PAHs) in the plant tissues were increased. PMID:26366627

  10. Proteomic Analysis Revealed Nitrogen-mediated Metabolic, Developmental, and Hormonal Regulation of Maize (Zea mays L.) Ear Growth

    PubMed Central

    Li, Chunjian; Li, Xuexian

    2012-01-01

    Optimal nitrogen (N) supply is critical for achieving high grain yield of maize. It is well established that N deficiency significantly reduces grain yield and N oversupply reduces N use efficiency without significant yield increase. However, the underlying proteomic mechanism remains poorly understood. The present field study showed that N deficiency significantly reduced ear size and dry matter accumulation in the cob and grain, directly resulting in a significant decrease in grain yield. The N content, biomass accumulation, and proteomic variations were further analysed in young ears at the silking stage under different N regimes. N deficiency significantly reduced N content and biomass accumulation in young ears of maize plants. Proteomic analysis identified 47 proteins with significant differential accumulation in young ears under different N treatments. Eighteen proteins also responded to other abiotic and biotic stresses, suggesting that N nutritional imbalance triggered a general stress response. Importantly, 24 proteins are involved in regulation of hormonal metabolism and functions, ear development, and C/N metabolism in young ears, indicating profound impacts of N nutrition on ear growth and grain yield at the proteomic level. PMID:22936831

  11. Emission of herbivore elicitor-induced sesquiterpenes is regulated by stomatal aperture in maize (Zea mays) seedlings.

    PubMed

    Seidl-Adams, I; Richter, A; Boomer, K B; Yoshinaga, N; Degenhardt, J; Tumlinson, J H

    2015-01-01

    Maize seedlings emit sesquiterpenes during the day in response to insect herbivory. Parasitoids and predators use induced volatile blends to find their hosts or prey. To investigate the diurnal regulation of biosynthesis and emission of induced sesquiterpenes, we applied linolenoyl-L-glutamine (LG) to maize seedlings in the morning or evening using a cut-stem assay and tracked farnesene emission, in planta accumulation, as well as transcript levels of farnesyl pyrophosphate synthase 3 (ZmFPPS3) and terpene synthase10 (ZmTPS10) throughout the following day. Independent of time of day of LG treatment, maximum transcript levels of ZmFPPS3 and ZmTPS10 occurred within 3-4 h after elicitor application. The similarity between the patterns of farnesene emission and in planta accumulation in light-exposed seedlings in both time courses suggested unobstructed emission in the light. After evening induction, farnesene biosynthesis increased dramatically during early morning hours. Contrary to light-exposed seedlings dark-kept seedlings retained the majority of the synthesized farnesene. Two treatments to reduce stomatal aperture, dark exposure at midday, and abscisic acid treatment before daybreak, resulted in significantly reduced amounts of emitted and significantly increased amounts of in planta accumulating farnesene. Our results suggest that stomata not only play an important role in gas exchange for primary metabolism but also for indirect plant defences. PMID:24725255

  12. Event-specific quantitative detection of nine genetically modified maizes using one novel standard reference molecule.

    PubMed

    Yang, Litao; Guo, Jinchao; Pan, Aihu; Zhang, Haibo; Zhang, Kewei; Wang, Zhengming; Zhang, Dabing

    2007-01-10

    With the development of genetically modified organism (GMO) detection techniques, the Polymerase Chain Reaction (PCR) technique has been the mainstay for GMO detection, and real-time PCR is the most effective and important method for GMO quantification. An event-specific detection strategy based on the unique and specific integration junction sequences between the host plant genome DNA and the integrated gene is being developed for its high specificity. This study establishes the event-specific detection methods for TC1507 and CBH351 maizes. In addition, the event-specific TaqMan real-time PCR detection methods for another seven GM maize events (Bt11, Bt176, GA21, MON810, MON863, NK603, and T25) were systematically optimized and developed. In these PCR assays, the fluorescent quencher, TAMRA, was dyed on the T-base of the probe at the internal position to improve the intensity of the fluorescent signal. To overcome the difficulties in obtaining the certified reference materials of these GM maizes, one novel standard reference molecule containing all nine specific integration junction sequences of these GM maizes and the maize endogenous reference gene, zSSIIb, was constructed and used for quantitative analysis. The limits of detection of these methods were 20 copies for these different GM maizes, the limits of quantitation were about 20 copies, and the dynamic ranges for quantification were from 0.05 to 100% in 100 ng of DNA template. Furthermore, nine groups of the mixed maize samples of these nine GM maize events were quantitatively analyzed to evaluate the accuracy and precision. The accuracy expressed as bias varied from 0.67 to 28.00% for the nine tested groups of GM maize samples, and the precision expressed as relative standard deviations was from 0.83 to 26.20%. All of these indicated that the established event-specific real-time PCR detection systems and the reference molecule in this study are suitable for the identification and quantification of these GM

  13. First report of Dolichozele koebelei Viereck, 1911 (Hymenoptera: Braconidae) on larvae of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) in maize (Zea mays L.) under different cropping systems.

    PubMed

    Silva, R B; Cruz, I; Penteado-Dias, A M

    2014-08-01

    In the context of the modern agriculture, pest control is important in order to increase productivity in maize (Zea mays L.). However, this control should be done rationally, prioritising environmentally safer methods such as biological control. This paper aims to report the occurrence of Dolichozele koebelei Viereck, 1911 (Hymenoptera: Braconidae) in Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) larvae collected in maize subjected to different cropping systems. The experiment was conducted at the Centro Nacional de Pesquisa de Milho e Sorgo (CNPMS) in Sete Lagoas, Minas Gerais State, Brazil, using organic and conventional production. Ten plants were sampled from each of the 24 plots and for each production system, three times a week during the entire cycle of maize (variety BR 106). In the laboratory, larvae were distributed in individual rearing containers with artificial diet until the end of the biological cycle. An increased number of S. frugiperda larvae was observed in organic single crop maize; hence a higher percentage of S. frugiperda larvae parasitised by Hymenoptera and Diptera also occurred in the maize under this production system. Dolichozele koebelei had not yet been described in association with larvae of S. frugiperda. The percentage of parasitism of S. frugiperda larvae was high in both experiments, indicating the importance of natural control agents in reducing the population density of S. frugiperda, and especially the importance of an appropriate crop management. PMID:25627388

  14. Phytotoxicity of brominated diphenyl ether-47 (BDE-47) and its hydroxylated and methoxylated analogues (6-OH-BDE-47 and 6-MeO-BDE-47) to maize (Zea mays L.).

    PubMed

    Xu, Xuehui; Huang, Honglin; Wen, Bei; Wang, Sen; Zhang, Shuzhen

    2015-03-16

    Polybrominated diphenyl ethers (PBDEs), methoxylated PBDEs (MeO-PBDEs), and hydroxylated PBDEs (OH-PBDEs) are widely found in various environmental media, which is of concern given their biological toxicity. In this study, the phytotoxicities of BDE-47, 6-MeO-BDE-47, and 6-OH-BDE-47 to maize (Zea mays L.) were investigated by an in vivo exposure experiment. Results showed that BDE-47, 6-MeO-BDE-47, and 6-OH-BDE-47 inhibited seed germination and seedling development, and elevated malondialdehyde (MDA), carbonyl groups, and phosphorylated histone H2AX levels in maize roots, suggesting the inducement of lipid peroxidation, protein carbonylation, and DNA damage to maize. Exposure to BDE-47, 6-MeO-BDE-47, and 6-OH-BDE-47 caused the overproduction of H2O2, O2(•-), and •OH, and elevated the activities of antioxidant enzymes in the roots. In addition, 6-OH-BDE-47 caused more severe damage and reactive oxygen species (ROS) generation in maize than did BDE-47 and 6-MeO-BDE-47. These results demonstrated the phytotoxicities of BDE-47, 6-OH-BDE-47, and 6-MeO-BDE-47 to maize, and clarified that overproduction of ROS was the key mechanism leading to toxicity. This study offers useful information for a more comprehensive understanding of the environmental behaviors and toxicities of PBDEs, MeO-PBDEs, and OH-PBDEs. PMID:25654621

  15. Arsenic species in broiler (Gallus gallus domesticus) litter, soils, maize (Zea mays L.), and groundwater from litter-amended fields.

    PubMed

    D'Angelo, Elisa; Zeigler, Georgia; Beck, E Glenn; Grove, John; Sikora, Frank

    2012-11-01

    Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus) often contain high levels of arsenic (As) when organoarsenical roxarsone and p-arsanilic acid are included in feed to combat disease and improve weight gain of the birds. This study was conducted to determine As levels and species in litter from three major broiler producing companies, and As levels in soils, corn tissue (Zea mays L.), and groundwater in fields where litter was applied. Total As in litter from the three different integrators ranged between <1 and 44 mg kg(-1). Between 15 and 20% of total As in litter consisted of mostly of arsenate, with smaller amounts of roxarsone and several transformation products that were extractable with phosphate buffer. Soils amended with litter had higher levels of bioavailable As (extractable with Mehlich 3 solution and taken up by corn leaves). Arsenic concentrations in plant tissue and groundwater, however, were below the World Health Organization thresholds, which was attributed to strong sorption/precipitation of arsenate in Fe- and Al-rich soils. Ecological impacts of amending soils with As-laden litter depend on the As species in the litter, and chemical and physical properties of soil that strongly affect As mobility and bioavailability in the environment. PMID:23010102

  16. Study of photosynthetic pigments changes of maize (Zea mays L.) under nano Tio2 spraying at various growth stages.

    PubMed

    Morteza, Elham; Moaveni, Payam; Farahani, Hossein Aliabadi; Kiyani, Mohammad

    2013-12-01

    Tests were done on the effects of treatments of titanium dioxide spray on corn (Zea mays L.). The study was conducted as a factorial experiment in a randomized complete block design with four replications. Treatments consisted of two factors; the first factor was stage of plant growth that spraying was applied (vegetative stage, appearance of male flowers and female flowers); and the second factor was that of different concentrations of titanium dioxide nanoparticles (Tio2) that consisted of spray with water (control), titanium dioxide or bulk, nano titanium dioxide at concentrations of 0.01% and 0.03%. Results showed that effect of nano Tio2 was significant on chlorophyll content (a and b), total chlorophyll (a + b), chlorophyll a/b, carotenoids and anthocyanins. The maximum amount of pigment was recorded from the treatment of nano Tio2 spray at the reproductive stage (appearance of male and female flowers) in comparison with control. Thus, an application of nanoparticles (nanao Tio2) can facilitate an increase in crop yield, especially corn yield. PMID:23847752

  17. In vitro oxidation of indoleacetic acid by soluble auxin-oxidases and peroxidases from maize roots. [Zea mays L

    SciTech Connect

    Beffa, R.; Martin, H.V.; Pilet, P.E. )

    1990-10-01

    Soluble auxin-oxidases were extracted from Zea mays L. cv LG11 apical root segments and partially separated from peroxidases (EC 1.11.1.7) by size-exclusion chromatography. Auxin-oxidases were resolved into one main peak corresponding to a molecular mass of 32.5 kilodaltons and a minor peak at 54.5 kilodaltons. Peroxidases were separated into at least four peaks, with molecular masses from 32.5 to 78 kilodaltons. In vitro activity of indoleacetic acid-oxidases was dependent on the presence of MnCl{sub 2} and p-coumaric acid. Compound(s) present in the crude extract and several synthetic auxin transport inhibitors (including 2,3,5-triiodobenzoic acid and N-1-naphthylphthalamic acid) inhibited auxin-oxidase activity, but had no effect on peroxidases. The products resulting from the in vitro enzymatic oxidation of ({sup 3}H)indoleacetic acid were separated by HPLC and the major metabolite was found to cochromatograph with indol-3yl-methanol.

  18. Carbon nanofibers suppress fungal inhibition of seed germination of maize (Zea mays) and barley (Hordeum vulgare L.) crop

    NASA Astrophysics Data System (ADS)

    Joshi, Anjali; Sharma, Arti; Nayyar, Harsh; Verma, Gaurav; Dharamvir, Keya

    2015-08-01

    Carbon nanofibers (CNFs) are one of allotropes of carbon, consists of graphene layers arrangement in the form of stacked cones or like a cup diameter in nanometer and several millimeters in length. Their extraordinary mechanical, chemical and electronic properties are due to their small size. CNFs have been successfully applied in field of medicine in variety of diagnostic methods. They proven to be an excellent system for drug delivery, tissue regeneration, biosensor etc. This research focuses the applications of CNFs in all fields of Agriculture. In the we treated some fungal disease seed of maize and barley using functionalised CNFs. We find that the tested seeds grow just as well as the healthy seeds whereas the untreated fungal disease seeds, by themselves show very poor germination and seedling growth. This simple experiment shows the extraordinary ability of Carbon nanofibers in carrying effectively inside the germinated seeds.

  19. Carbon nanofibers suppress fungal inhibition of seed germination of maize (Zea mays) and barley (Hordeum vulgare L.) crop

    SciTech Connect

    Joshi, Anjali Sharma, Arti; Nayyar, Harsh; Verma, Gaurav; Dharamvir, Keya

    2015-08-28

    Carbon nanofibers (CNFs) are one of allotropes of carbon, consists of graphene layers arrangement in the form of stacked cones or like a cup diameter in nanometer and several millimeters in length. Their extraordinary mechanical, chemical and electronic properties are due to their small size. CNFs have been successfully applied in field of medicine in variety of diagnostic methods. They proven to be an excellent system for drug delivery, tissue regeneration, biosensor etc. This research focuses the applications of CNFs in all fields of Agriculture. In the we treated some fungal disease seed of maize and barley using functionalised CNFs. We find that the tested seeds grow just as well as the healthy seeds whereas the untreated fungal disease seeds, by themselves show very poor germination and seedling growth. This simple experiment shows the extraordinary ability of Carbon nanofibers in carrying effectively inside the germinated seeds.

  20. Mapping QTLs for root system architecture of maize (Zea mays L.) in the field at different developmental stages.

    PubMed

    Cai, Hongguang; Chen, Fanjun; Mi, Guohua; Zhang, Fusuo; Maurer, Hans Peter; Liu, Wenxin; Reif, Jochen C; Yuan, Lixing

    2012-10-01

    Root system architecture (RSA) is seldom considered as a selection criterion to improve yield in maize breeding, mainly because of the practical difficulties with their evaluation under field conditions. In the present study, phenotypic profiling of 187 advanced-backcross BC(4)F(3) maize lines (Ye478 × Wu312) was conducted at different developmental stages under field conditions at two locations (Dongbeiwang in 2007 and Shangzhuang in 2008) for five quantitative root traits. The aims were to (1) understand the genetic basis of root growth in the field; (2) investigate the contribution of root traits to grain yield (GY); and (3) detect QTLs controlling root traits at the seedling (I), silking (II) and maturation (III) stages. Axial root (AR)-related traits showed higher heritability than lateral root (LR)-related traits, which indicated stronger environmental effects on LR growth. Among the three developmental stages, root establishment at stage I showed the closest relationship with GY (r = 0.33-0.43, P < 0.001). Thirty QTLs for RSA were detected in the BC(4)F(3) population and only 13.3 % of the QTLs were detected at stage III. Most important QTLs for root traits were located on chromosome 6 near the locus umc1257 (bin 6.02-6.04) at stage I, and chromosome 10 near the locus umc2003 (bin 10.04) for number of AR across all three developmental stages. The regions of chromosome 7 near the locus bnlg339 (bin 7.03) and chromosome 1 near the locus bnlg1556 (bin 1.07) harbored QTLs for both GY- and LR-related traits at stages I and II, respectively. These results help to understand the genetic basis of root development under field conditions and their contribution to grain yield. PMID:22718302

  1. Polymorphisms in O-methyltransferase genes are associated with stover cell wall digestibility in European maize (Zea mays L.)

    PubMed Central

    2010-01-01

    Background OMT (O-methyltransferase) genes are involved in lignin biosynthesis, which relates to stover cell wall digestibility. Reduced lignin content is an important determinant of both forage quality and ethanol conversion efficiency of maize stover. Results Variation in genomic sequences coding for COMT, CCoAOMT1, and CCoAOMT2 was analyzed in relation to stover cell wall digestibility for a panel of 40 European forage maize inbred lines, and re-analyzed for a panel of 34 lines from a published French study. Different methodologies for association analysis were performed and compared. Across association methodologies, a total number of 25, 12, 1, 6 COMT polymorphic sites were significantly associated with DNDF, OMD, NDF, and WSC, respectively. Association analysis for CCoAOMT1 and CCoAOMT2 identified substantially fewer polymorphic sites (3 and 2, respectively) associated with the investigated traits. Our re-analysis on the 34 lines from a published French dataset identified 14 polymorphic sites significantly associated with cell wall digestibility, two of them were consistent with our study. Promising polymorphisms putatively causally associated with variability of cell wall digestibility were inferred from the total number of significantly associated SNPs/Indels. Conclusions Several polymorphic sites for three O-methyltransferase loci were associated with stover cell wall digestibility. All three tested genes seem to be involved in controlling DNDF, in particular COMT. Thus, considerable variation among Bm3 wildtype alleles can be exploited for improving cell-wall digestibility. Target sites for functional markers were identified enabling development of efficient marker-based selection strategies. PMID:20152036

  2. 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

  3. The Genetic Basis of Heterosis: Multiparental Quantitative Trait Loci Mapping Reveals Contrasted Levels of Apparent Overdominance Among Traits of Agronomical Interest in Maize (Zea mays L.)

    PubMed Central

    Larièpe, A.; Mangin, B.; Jasson, S.; Combes, V.; Dumas, F.; Jamin, P.; Lariagon, C.; Jolivot, D.; Madur, D.; Fiévet, J.; Gallais, A.; Dubreuil, P.; Charcosset, A.; Moreau, L.

    2012-01-01

    Understanding the genetic bases underlying heterosis is a major issue in maize (Zea mays L.). We extended the North Carolina design III (NCIII) by using three populations of recombinant inbred lines derived from three parental lines belonging to different heterotic pools, crossed with each parental line to obtain nine families of hybrids. A total of 1253 hybrids were evaluated for grain moisture, silking date, plant height, and grain yield. Quantitative trait loci (QTL) mapping was carried out on the six families obtained from crosses to parental lines following the “classical” NCIII method and with a multiparental connected model on the global design, adding the three families obtained from crosses to the nonparental line. Results of the QTL detection highlighted that most of the QTL detected for grain yield displayed apparent overdominance effects and limited differences between heterozygous genotypes, whereas for grain moisture predominance of additive effects was observed. For plant height and silking date results were intermediate. Except for grain yield, most of the QTL identified showed significant additive-by-additive epistatic interactions. High correlation observed between heterosis and the heterozygosity of hybrids at markers confirms the complex genetic basis and the role of dominance in heterosis. An important proportion of QTL detected were located close to the centromeres. We hypothesized that the lower recombination in these regions favors the detection of (i) linked QTL in repulsion phase, leading to apparent overdominance for heterotic traits and (ii) linked QTL in coupling phase, reinforcing apparent additive effects of linked QTL for the other traits. PMID:22135356

  4. The Use of Targeted Marker Subsets to Account for Population Structure and Relatedness in Genome-Wide Association Studies of Maize (Zea mays L.)

    PubMed Central

    Chen, Angela H.; Lipka, Alexander E.

    2016-01-01

    A typical plant genome-wide association study (GWAS) uses a mixed linear model (MLM) that includes a trait as the response variable, a marker as an explanatory variable, and fixed and random effect covariates accounting for population structure and relatedness. Although effective in controlling for false positive signals, this model typically fails to detect signals that are correlated with population structure or are located in high linkage disequilibrium (LD) genomic regions. This result likely arises from each tested marker being used to estimate population structure and relatedness. Previous work has demonstrated that it is possible to increase the power of the MLM by estimating relatedness (i.e., kinship) with markers that are not located on the chromosome where the tested marker resides. To quantify the amount of additional significant signals one can expect using this so-called K_chr model, we reanalyzed Mendelian, polygenic, and complex traits in two maize (Zea mays L.) diversity panels that have been previously assessed using the traditional MLM. We demonstrated that the K_chr model could find more significant associations, especially in high LD regions. This finding is underscored by our identification of novel genomic signals proximal to the tocochromanol biosynthetic pathway gene ZmVTE1 that are associated with a ratio of tocotrienols. We conclude that the K_chr model can detect more intricate sources of allelic variation underlying agronomically important traits, and should therefore become more widely used for GWAS. To facilitate the implementation of the K_chr model, we provide code written in the R programming language. PMID:27233668

  5. The Use of Targeted Marker Subsets to Account for Population Structure and Relatedness in Genome-Wide Association Studies of Maize (Zea mays L.).

    PubMed

    Chen, Angela H; Lipka, Alexander E

    2016-01-01

    A typical plant genome-wide association study (GWAS) uses a mixed linear model (MLM) that includes a trait as the response variable, a marker as an explanatory variable, and fixed and random effect covariates accounting for population structure and relatedness. Although effective in controlling for false positive signals, this model typically fails to detect signals that are correlated with population structure or are located in high linkage disequilibrium (LD) genomic regions. This result likely arises from each tested marker being used to estimate population structure and relatedness. Previous work has demonstrated that it is possible to increase the power of the MLM by estimating relatedness (i.e., kinship) with markers that are not located on the chromosome where the tested marker resides. To quantify the amount of additional significant signals one can expect using this so-called K_chr model, we reanalyzed Mendelian, polygenic, and complex traits in two maize (Zea mays L.) diversity panels that have been previously assessed using the traditional MLM. We demonstrated that the K_chr model could find more significant associations, especially in high LD regions. This finding is underscored by our identification of novel genomic signals proximal to the tocochromanol biosynthetic pathway gene ZmVTE1 that are associated with a ratio of tocotrienols. We conclude that the K_chr model can detect more intricate sources of allelic variation underlying agronomically important traits, and should therefore become more widely used for GWAS. To facilitate the implementation of the K_chr model, we provide code written in the R programming language. PMID:27233668

  6. Detection of genetically modified maize in processed foods sold commercially in iran by qualitative PCR.

    PubMed

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer's right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  7. Detection of Genetically Modified Maize in Processed Foods Sold Commercially in Iran by Qualitative PCR

    PubMed Central

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer’s right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  8. Phosphate solubilizing rhizobacteria from an organic farm and their influence on the growth and yield of maize (Zea mays L.).

    PubMed

    Kaur, Gurdeep; Reddy, M Sudhakara

    2013-01-01

    Organic farming is gaining popularity all over the world as it avoids the use of synthetic chemicals. Plant production in organic farming mainly depends on nutrient release as a function of mineralization processes in soils. In the present study, efficient phosphate mineralizing bacteria were isolated and their efficacy tested in plant mineral uptake and soil fertility of an organic field. Amongst 12 P-solubilizing bacteria (PSB) isolated from an organic field, two isolates were selected for field inoculation based on their rock phosphate (RP) solubilzing ability, exudation of organic acids, phosphatase and phytase activity and production of indole acetic acid and siderophores. On the basis of biochemical characterization and 16S rRNA sequence analysis, these isolates were identified as Pantoea cypripedii (PSB-3) and Pseudomonas plecoglossicida (PSB-5). These isolates significantly increased yield and total P uptake in maize. Soil analysis showed that available P, organic carbon and soil enzyme activities were significantly increased. Present study results suggested that inoculation of these bacteria has great application potential in improving the crop yield and soil fertility in organic farming. PMID:24005179

  9. The pam1 gene is required for meiotic bouquet formation and efficient homologous synapsis in maize (Zea mays L.).

    PubMed Central

    Golubovskaya, Inna N; Harper, Lisa C; Pawlowski, Wojciech P; Schichnes, Denise; Cande, W Zacheus

    2002-01-01

    The clustering of telomeres on the nuclear envelope (NE) during meiotic prophase to form the bouquet arrangement of chromosomes may facilitate homologous chromosome synapsis. The pam1 (plural abnormalities of meiosis 1) gene is the first maize gene that appears to be required for telomere clustering, and homologous synapsis is impaired in pam1. Telomere clustering on the NE is arrested or delayed at an intermediate stage in pam1. Telomeres associate with the NE during the leptotene-zygotene transition but cluster slowly if at all as meiosis proceeds. Intermediate stages in telomere clustering including miniclusters are observed in pam1 but not in wild-type meiocytes. The tight bouquet normally seen at zygotene is a rare event. In contrast, the polarization of centromeres vs. telomeres in the nucleus at the leptotene-zygotene transition is the same in mutant and wild-type cells. Defects in homologous chromosome synapsis include incomplete synapsis, nonhomologous synapsis, and unresolved interlocks. However, the number of RAD51 foci on chromosomes in pam1 is similar to that of wild type. We suggest that the defects in homologous synapsis and the retardation of prophase I arise from the irregularity of telomere clustering and propose that pam1 is involved in the control of bouquet formation and downstream meiotic prophase I events. PMID:12524364

  10. Frequent Loss of the En Transposable Element after Excision and Its Relation to Chromosome Replication in Maize (Zea Mays L.)

    PubMed Central

    Dash, S.; Peterson, P. A.

    1994-01-01

    A model of En transposition during chromosome replication is presented following a study of somatic events associated with the transposition of En in the endosperm tissue of the maize kernel. Two supporting assays, the excision and the postexcision events, were used in following these events. The excision of the En transposon has been monitored in the starch-producing endosperm tissue by using the wx-844 autonomously mutable allele, and events after excision have been monitored by using various reporter alleles of the En-I (Spm-dSpm) system. The initial observations revealed an unusually large amount of loss of the En transposon following its excision from the wx-844 allele. Subsequent analysis of the somatic events using the a2-m1 reporter allele to monitor the dosage of En suggested that the large amount of loss would result from the transposition of En during chromosome replication. Transposition of En from a replicated segment of the chromosome to another site that has also undergone replication explains most of the somatic events observed. PMID:8150289