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The composition of gluten proteins and their effect on the rheological properties of gluten
124-129Views:119Wheat is the major cereal component of bread in the world and is grown worldwide. Of the cereals only the bread wheats – and less the triticale – includes storage proteins that play an important role in the performance of gluten. Proteins of gluten complex may be present in two classes:
− low molecular weight (gliadin-) components, and
− high molecular weight (glutenin-) components.
Gliadins shown appreciable heterogenity and can be separated into 40-50 components with gel electrophoresis. The composition of gliadins is employable for the identification the wheat varieties and to investigate the varieties. In the decreasing electrophoretic mobility sequence may be distinguish α-, β-, γ- and ω-gliadins. A glutenin subunits may be include in two classes:
− high molecular weight glutenin subunits (HMW-GS),
− low molecular weight glutenin subunits (LMW-GS).
Wheat varieties can be identified by glutenin and their quality selection is also possible. The gliadin’s polypeptides encoding genes are located on the short arm of chromosomes 1A, 1B and 1D, 6A, 6B and 6D. Genetic coding for HMW subunits is located on the long arms of chromosomes 1A, 1B and 1D, the LMW-GS are also located on chromosomes 1A, 1B and 1D (Glu-3 loci) near the gliadin-coding loci.
Storage proteins affect the rheological properties of gluten by two factors:
1. The quality and quantity of the protein components of the gluten complex,
2. The interactions between the protein fractions. -
DHAC-induced transgene overexpression in 35S-gshI GMO poplar (Populus × canescens)
78-83Views:33Relative gene expression levels of transgene gshI (γ-glutamylcysteine synthetase cloned from E. coli) were analyzed by qRT-PCR in two transgenic poplar (Populus × canescens) clones (11ggs and 6lgl) and wild type (WT). An extremely high expression level of transgene gshI was observed in the 6lgl clone (13.5-fold) compared to 11ggs (1.0) samples, which level was doubled (1.8-fold) in the DHAC (5.6-dihydro-5'-azacytidine hydrochloride) treated (at 10-4 M for 7 days) 6lgl samples but not in the 11ggs clone (0.4-fold). Contrary to this result, relative copy number of transgene gshI in the 6lgl clone was found to be less 60% less (1.0) then in the 11ggs samples (1.6). Relative expression levels of proper poplar gene gsh1-poplar showed significantly higher responsiveness to DHAC treatment than transgene gshI with the highest expression level in the untransformed (WT) poplar
clone (19.7-fold) compared to transformed 6lgl (8.7-fold) and 11ggs (2.5-fold) clones. For internal controls constitutively expressed housekeeping genes a-tubulin were applied. For data analysis, the 2−ΔΔCt method was used. DHAC applied in long-term cultures (27 days) at low concentrations (10-8 – 10-6 M) showed morphogenetic activity by initiating de novo root development of leaf discs. -
Development of a New Maize (Zea mays L.) Breeding Program
25-30Views:91Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.
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Q-PCR analysis of the resistance of Hungarian Botrytis cinerea isolates toward azoxystrobin
41-44Views:76The genes being in the mitochondrial DNA primarily encode the enzymes of cellular respiration. Fungicides belonging to the family of quinol oxidase inhibitors (QoIs) play on important role in the protection against several plant diseases caused by fungi. These fungicides bind to the cytochrome bc1 complex so they block electron transport between cytochrome b and cytochrome c1. This way these fungicides inhibit the ATP synthesis consequently they inhibit the mitochondrial respiration. The QoI resistance has two mechanisms. One of them is the point mutation of the cytochrome b gene (CYTB), e.g. the substitution of a single glycine by alanine at position 143 results in high-resistance. The other is the cyanide-resistant alternative respiration sustained by the alternative oxidase.
In a cell there are several mitochondria. The phenomenon when the genomes of all mitochondria in the cell are identical is called homoplazmy. If in the cell there is wild and mutant mitochondrial DNA this is called heteroplasmy. Whether the mutation in the mitochondria causes fenotypical diversity or does not depend on the dose, i.e. it depends on the percentage of the changed mitochondrials. During our work we investigated Botrytis cinerea single spore isolates which have been collected in 2008-2009 on different host plants. Our goal was to decide whether heteroplasmy influences the level of resistance. We managed to detect the change of the level of heteroplasmy, so the change the level of the resistance due to the treatment with fungicide.