Transgenic barley: A prospective tool for biotechnology and agriculture

Barley (Hordeum vulgare L.) is one of the founder crops of agriculture, and today it is the fourth most important cereal grain worldwide. Barley is used as malt in brewing and distilling industry, as an additive for animal feed, and as a component of various food and bread for human consumption. Progress in stable genetic transformation of barley ensures a potential for improvement of its agronomic performance or use of barley in various biotechnological and industrial applications. Recently, barley grain has been successfully used in molecular farming as a promising bioreactor adapted for production of human therapeutic proteins or animal vaccines. In addition to development of reliable transformation technologies, an extensive amount of various barley genetic resources and tools such as sequence data, microarrays, genetic maps, and databases has been generated. Current status on barley transformation technologies including gene transfer techniques, targets, and progeny stabilization, recent trials for improvement of agricultural traits and performance of barley, especially in relation to increased biotic and abiotic stress tolerance, and potential use of barley grain as a protein production platform have been reviewed in this study. Overall, barley represents a promising tool for both agricultural and biotechnological transgenic approaches, and is considered an ancient but rediscovered crop as a model industrial platform for molecular farming.     

Temperate trees and shrubs as global invaders: the relationship between invasiveness and native distribution depends on biological traits

Many woody plants have been recently recognized as major invasive species with serious impacts on species diversity and functioning of invaded ecosystems. We evaluated the global invasion success of temperate trees and shrubs with native ranges in central Europe and explored the role of their native distribution and that of biological traits in determining whether they have become invasive in other parts of the world. Of the 94 species forming the source-area species pool, 27 % are known to be invasive in at least one region of the world. Generalized linear models on phylogenetically non-informed analyses revealed that tall woody plants flowering early in the season, and occupying many grid cells in the native range are significantly more likely to become successful invaders than species not possessing these traits. However, other traits can partly reduce the disadvantages resulting from low regional frequencies in the native range and consequent lower probability of them being introduced elsewhere. Species that do not depend for reproduction on another individual, those pollinated by wind and dispersed by animals are likely to become invasive even if they do not have extensive native distributions. However, of these traits only the regional frequency in the native range remained significant when phylogenetic relationships were taken into account. This indicates that the effect of the regional frequency is generic, valid across all woody species, and fine-tuned by advantageous biological traits inherited from common ancestors, shared by groups of phylogenetically-related species. Traits that only appeared significant in the phylogenetically non-informed analyses should be considered as specific for shrubs and trees of central Europe. Mode of reproduction was only significant in the phylogenetically-informed analysis, indicating that reproduction exclusively by seed favours invasiveness of woody species. From the management perspective, however, the predictive value of some traits is not diminished by them being phylogenetically constrained since we are not interested whether the behaviour of particular species is a result of evolutionary history but how we can treat specific cases of invasion.     

Mapping of single-copy genes by TSA-FISH in the codling moth, <Emphasis Type="Italic">Cydia pomonella</Emphasis>

Background

We work on the development of transgenic sexing strains in the codling moth, Cydia pomonella (Tortricidae), which would enable to produce male-only progeny for the population control of this pest using sterile insect technique (SIT). To facilitate this research, we have developed a number of cytogenetic and molecular tools, including a physical map of the codling moth Z chromosome using BAC-FISH (fluorescence in situ hybridization with bacterial artificial chromosome probes). However, chromosomal localization of unique, single-copy sequences such as a transgene cassette by conventional FISH remains challenging. In this study, we adapted a FISH protocol with tyramide signal amplification (TSA-FISH) for detection of single-copy genes in Lepidoptera. We tested the protocol with probes prepared from partial sequences of Z-linked genes in the codling moth.

Results

Using a modified TSA-FISH protocol we successfully mapped a partial sequence of the Acetylcholinesterase 1 (Ace-1) gene to the Z chromosome and confirmed thus its Z-linkage. A subsequent combination of BAC-FISH with BAC probes containing anticipated neighbouring Z-linked genes and TSA-FISH with the Ace-1 probe allowed the integration of Ace-1 in the physical map of the codling moth Z chromosome. We also developed a two-colour TSA-FISH protocol which enabled us simultaneous localization of two Z-linked genes, Ace-1 and Notch, to the expected regions of the Z chromosome.

Conclusions

We showed that TSA-FISH represents a reliable technique for physical mapping of genes on chromosomes of moths and butterflies. Our results suggest that this technique can be combined with BAC-FISH and in the future used for physical localization of transgene cassettes on chromosomes of transgenic lines in the codling moth or other lepidopteran species. Furthermore, the developed protocol for two-colour TSA-FISH might become a powerful tool for synteny mapping in non-model organisms.

     

Improvement of Pro-Oxidant Capacity of Protocatechuic Acid by Esterification

Pro-oxidant effects of phenolic compounds are usually correlated to the one-electron redox potential of the phenoxyl radicals. Here we demonstrated that, besides their oxidizability, hydrophobicity can also be a decisive factor. We found that esterification of protocatechuic acid (P0) provoked a profound influence in its pro-oxidant capacity. The esters bearing alkyl chains containing two (P2), four (P4) and seven (P7) carbons, but not the acid precursor (P0), were able to exacerbate the oxidation of trolox, α-tocopherol and rifampicin. This effect was also dependent on the catechol moiety, since neither gallic acid nor butyl gallate showed any pro-oxidant effects. A comparison was also made with apocynin, which is well-characterized regarding its pro-oxidant properties. P7 was more efficient than apocynin regarding co-oxidation of trolox. However, P7 was not able to co-oxidize glutathione and NADH, which are targets of the apocynin radical. A correlation was found between pro-oxidant capacity and the stability of the radicals, as suggested by the intensity of the peak current in the differential pulse voltammetry experiments. In conclusion, taking into account that hydroquinone and related moieties are frequently found in biomolecules and quinone-based chemotherapeutics, our demonstration that esters of protocatechuic acid are specific and potent co-catalysts in their oxidations may be very relevant as a pathway to exacerbate redox cycling reactions, which are usually involved in their biological and pharmacological mechanisms of action.     

Seasonal Photochemical Transformations of Nitrogen Species in a Forest Stream and Lake

The photochemical release of inorganic nitrogen from dissolved organic matter is an important source of bio-available nitrogen (N) in N-limited aquatic ecosystems. We conducted photochemical experiments and used mathematical models based on pseudo-first-order reaction kinetics to quantify the photochemical transformations of individual N species and their seasonal effects on N cycling in a mountain forest stream and lake (Plešné Lake, Czech Republic). Results from laboratory experiments on photochemical changes in N speciation were compared to measured lake N budgets. Concentrations of organic nitrogen (N_org; 40–58 µmol L⁻¹) decreased from 3 to 26% during 48-hour laboratory irradiation (an equivalent of 4–5 days of natural solar insolation) due to photochemical mineralization to ammonium (NH₄ ⁺) and other N forms (N_x; possibly N oxides and N₂). In addition to N_org mineralization, N_x also originated from photochemical nitrate (NO₃ ⁻) reduction. Laboratory exposure of a first-order forest stream water samples showed a high amount of seasonality, with the maximum rates of N_org mineralization and NH₄ ⁺ production in winter and spring, and the maximum NO₃ ⁻ reduction occurring in summer. These photochemical changes could have an ecologically significant effect on NH₄ ⁺ concentrations in streams (doubling their terrestrial fluxes from soils) and on concentrations of dissolved N_org in the lake. In contrast, photochemical reactions reduced NO₃ ⁻ fluxes by a negligible (<1%) amount and had a negligible effect on the aquatic cycle of this N form.     

How laminin-1 can be recognized by the protozoan parasite Tritrichomonas foetus: possible role played by the extracellular matrix glycoprotein in both cytoadhesion and cytotoxicity exerted by the parasite

The isoform 1 of the extracellular matrix glycoprotein Laminin is known to be an important ligand for some parasitic protozoa including Trichomonas vaginalis. The bovine parasite Tritrichomonas foetus seems to display a similar recognition process to laminin-1, as some amino acid sequences found in the LNS module of laminin-1 can also be recognized by this parasite. Which of the laminin-1 residing adhesion sequences are recognized by T. foetus, and the role played by such a protein-cell recognition process in both cytoadhesion and cytotoxicity exerted by the parasite are the subjects briefly reviewed and discussed here.