Maternal effects influencing DNA endoreduplication in developing endosperm of Zea mays

Genome ◽  
1997 ◽  
Vol 40 (6) ◽  
pp. 798-805 ◽  
Author(s):  
R. V. Kowles ◽  
G. L. Yerk ◽  
K. M. Haas ◽  
R. L. Phillips
Keyword(s):  
Flow Cytometry ◽  
Zea Mays ◽  
Maternal Effect ◽  
Zea Mays L ◽  
Nuclear Genome ◽  
Dna Amplification ◽  
Endosperm Tissue ◽  
Flow Cytometry Data ◽  
Paternal Parent ◽  
Maize Kernels

A large proportion of the nuclei in developing endosperm of Zea mays L. undergoes endoreduplication. Nuclear preparations of the entire endosperm from maize kernels of inbred lines, their reciprocal hybrids, and in some cases, F2 and F3 endosperm tissue were evaluated using flow cytometry. Data relative to DNA endoreduplication patterns, percentage of nuclei undergoing endoreduplication, and mean DNA content per nucleus were obtained. The patterns of endoreduplication and extent of DNA amplification differ among some inbreds. In all experiments, the endoreduplication patterns show that the F1 endosperm is more similar to the maternal parent than to the paternal parent. F2 endosperms reveal little difference in endoreduplication patterns among individuals within an F2 family and no more variation than the F1 endosperms. In contrast, F3 endosperms showed greater variation among their endoreduplication patterns. These results indicate a maternal effect on endoreduplication; that is, the genotype of the maternal parent's nuclear genome exerts control over the endoreduplication activities of endosperm tissue.Key words: endosperm, endoreduplication, maternal effect, flow cytometry, Zea mays L.

scholarly journals Excision Patterns of Activator (Ac) and Dissociation (Ds) Elements in Zea mays L.: Implications for the Regulation of Transposition

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1851-1869 ◽  
Author(s):  
Manfred Heinlein
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Waxy Gene ◽  
Transposition Frequency ◽  
Cis Acting ◽  
Dosage Effects ◽  
In Trans ◽  
Ds Excision ◽  
Maize Kernels ◽  
Strong Contrast

The pattern of aleurone variegation of maize kernels carrying Ac and bz-m2(DI) as reporter allele for Ac activity depends on the dosage of both Ac and Ds. Alterations of Ac dosage can abolish Ds excision at certain times and allow it to occur at other times. wx-m7 and wx-m9 are different Ac insertions in the Waxy gene which have different dosage effects on Ds excision. Kernels, heterozygous for the two Ac alleles and being either wx-m7/wx-m7/wx-m9 or wx-m9/wx-m9/wx-m7 exhibit characteristic patterns of predominantly late excisions; this is in strong contrast to the pattern of early excisions present on wx-m7/wx-m7/wx-m7 homozygotes. This observation supports the hypothesis that the Ac alleles express different amounts of transposase (TPase) during development and that above a certain level of TPase transposition is inhibited. Furthermore, experimental results suggest that the frequency of Ac-induced events is influenced by the dosage and composition of the transactivated Ds or Ac allele. Thus, transposition frequency seems not to be exclusively determined in trans by the amount of active TPase, but also by specific cis-acting properties of the TPase substrate.

scholarly journals Maize (Zea Mays L) landraces from the southern region of Brazil: contamination by Fusarium sp, zearalenone, physical and mechanical characteristics of the kernels

2009 ◽  
Vol 52 (spe) ◽  
pp. 11-16 ◽  
Author(s):  
Tatiana Roselena de Oliveira ◽  
David de Souza Jaccoud-Filho ◽  
Luciana Henneberg ◽  
Milton Domingos Michel ◽  
Ivo Mottin Demiate ◽  
...  
Keyword(s):  
Zea Mays ◽  
Mechanical Characteristics ◽  
Zea Mays L ◽  
Southern Region ◽  
Fusarium Sp ◽  
Maize Kernels ◽  
Physical And Mechanical Characteristics

This work had as objectives the study of the physical and mechanical characteristics of maize kernels in relation to the contamination by Fusarium sp and by zearalenone in twenty landraces of maize from the southern region of Brazil. From the analyzed samples, 60 % has been considered to have a hard endosperm type and 40 % an intermediary one. A correlation between the physical and mechanical variables was observed as an indication that the higher is the proportion of hard endosperm, more dense will be the kernel and more force for its rupture will be necessary. The level of contamination by Fusarium sp was between 5.5 and 24.75% among the analyzed grains, correlating positively with the flotation index, indicating that the landraces of maize with a softer endosperm can present a higher contamination by this genus. The presence of zearalenone was verified in 75 % of the samples, in concentrations varying from 50 to 640 µg kg-1.

Some factors influencing electrolyte leakage from maize (Zea mays L.) kernels

1991 ◽  
Vol 1 (1) ◽  
pp. 15-20 ◽  
Author(s):  
H. Bruggink ◽  
H. L. Kraak ◽  
M. H. G. E. Dijkema ◽  
J. Bekendam
Keyword(s):  
Zea Mays ◽  
Moisture Content ◽  
Electrolyte Leakage ◽  
Zea Mays L ◽  
Mechanical Damage ◽  
Kernel Weight ◽  
Conductivity Measurements ◽  
Factors Influencing ◽  
Quality Testing ◽  
Maize Kernels

AbstractEven though the embryo of a maize (Zea mays L.) kernel contributes relatively little to total kernel weight, it is a main source of electrolytes which leach from the kernel during imbibition. Ageing of maize kernels for 18 days at 40°C and a moisture content of about 15% results in an increase of electrolyte leakage which almost exclusively originates from the embryo. The effect of ageing is most apparent after prolonged periods of imbibition. Mechanical damage increases leakage early during imbibition, the effect of damage being considerably larger for aged than for unaged kernels. The large amount of electrolytes measured after the first hour of imbibition of undamaged kernels comes mainly from the pericarp. The electrolyte content of the pericarp is variety dependent and may interfere with quality testing by conductivity measurements.

scholarly journals IDENTIFICAÇÃO MORFOLÓGICA E MOLECULAR DE Curvularia sp. AGENTE CAUSAL DA MANCHA FOLIAR DO MILHO

2017 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
DALMARCIA DE SOUZA CARLOS MOURÃO ◽  
SOLANGE APARECIDA SÁGIO ◽  
MICAELE RODRIGUES DE SOUZA ◽  
GIL RODRIGUES DOS SANTOS
Keyword(s):  
Zea Mays ◽  
Molecular Identification ◽  
Zea Mays L ◽  
Morphological Characteristics ◽  
Dna Amplification ◽  
Restriction Enzymes ◽  
Molecular Techniques ◽  
Cultivated Plants ◽  
Curvularia Lunata ◽  
Correct Identification

RESUMO - Fungos do gênero Curvularia são amplamente distribuídos ao redor do mundo, podendo estar associados a espécies vegetais, na forma saprofítica, endofítica ou como parasita. Espécies do referido gênero são responsáveis por diversas doenças em plantas cultivadas, causando principalmente manchas foliares. A correta identificação das espécies é importante para o conhecimento e manejo das doenças, sendo essas identificações baseadas principalmente em características morfológicas, como aspectos dos micélios, morfologia das hifas, formas e tamanho dos conídios. Entretanto, técnicas moleculares como a amplificação de genes específicos, além de análises do padrão de digestão de regiões ITS através de enzimas de restrição, têm contribuído para a identificação e diferenciação genética entre espécies. No presente trabalho foi realizada a caracterização morfológica e molecular de isolados de Curvularia oriundos de plantas de milho infectadas. Os isolados foram agrupados de acordo com a identificação morfológica e molecular, sendo que todos apresentaram o mesmo perfil de amplificação do DNA. As técnicas morfológicas e moleculares possibilitaram a caracterização de uma única espécie, Curvularia lunata.Palavras–chave: Zea mays L., Curvularia lunata, morfologia, DNA, perfil de restrição.MORPHOLOGICAL AND MOLECULAR IDENTIFICATION OF Curvularia sp.CAUSAL AGENT OF CORN LEAF STAINABSTRACT - Fungi of the genus Curvularia are widely distributed around the world and may be associated with plant species, in the saprophytic, endophytic or parasitic form. Species of this genus are responsible for several diseases in cultivated plants, causing mainly foliar stains. The correct identification of the species is important for the diseases knowledge and management, being these identifications based mainly on morphological characteristics as aspects of the mycelia, conidia forms and size, hyphae morphology. However, molecular techniques such as the amplification of specific genes, as well as digestion pattern analyzes of ITS regions through restriction enzymes, have contributed to the identification and genetic differentiation between species. In the present study, the morphological and molecular characterizations of Curvularia isolates from infected corn plants were realized. The isolates were grouped according to the morphological and molecular identification, all of which presented the same DNA amplification profile. Morphological and molecular techniques allowed the characterization of a single species, Curvularia lunata. Keywords: Zea mays L. Curvularia lunata, morphology, DNA, restriction profile.

scholarly journals Frequent loss of the En transposable element after excision and its relation to chromosome replication in maize (Zea mays L.).

Genetics ◽  
1994 ◽  
Vol 136 (2) ◽  
pp. 653-671 ◽  
Author(s):  
S Dash ◽  
P A Peterson
Keyword(s):  
Zea Mays ◽  
Transposable Element ◽  
Zea Mays L ◽  
Chromosome Replication ◽  
Endosperm Tissue ◽  
Maize Kernel ◽  
Mutable Allele

Abstract 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-1 (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.

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