Patrik Mészáros

Plant chitinase responses to different metal-type stresses reveal specificity

Key messageChitinases inGlycine maxroots specifically respond to different metal types and reveal a polymorphism that coincides with sensitivity to metal toxicity.AbstractPlants evolved various defense mechanisms to cope with metal toxicity. Chitinases (EC 3.2.1.14), belonging to so-called pathogenesis-related proteins, act as possible second line defense compounds in plants exposed to metals. In this work their activity was studied and compared in two selected soybean (Glycine max L.) cultivars, the metal-tolerant cv. Chernyatka and the sensitive cv. Kyivska 98. Roots were exposed to different metal(loid)s such as cadmium, arsenic and aluminum that are expected to cause toxicity in different ways. For comparison, a non-metal, NaCl, was applied as well. The results showed that the sensitivity of roots to different stressors coincides with the responsiveness of chitinases in total protein extracts. Moreover, detailed analyses of acidic and neutral proteins identified one polymorphic chitinase isoform that distinguishes between the two cultivars studied. This isoform was stress responsive and thus could reflect the evolutionary adaptation of soybean to environmental cues. Activities of the individual chitinases were dependent on metal type as well as the cultivar pointing to their more complex role in plant defense during this type of stress.

Molecular characterization and evolution of carnivorous sundew (Drosera rotundifolia L.) class V β-1,3-glucanase

AbstractMain conclusionA gene for β-1,3-glucanase was isolated from carnivorous sundew. It is active in leaves and roots, but not in digestive glands. Analyses in transgenic tobacco suggest its function in germination. Ancestral plant β-1,3-glucanases (EC 3.2.1.39) played a role in cell division and cell wall remodelling, but divergent evolution has extended their roles in plant defense against stresses to decomposition of prey in carnivorous plants. As available gene sequences from carnivorous plants are rare, we isolated a glucanase gene from roundleaf sundew (Drosera rotundifolia L.) by a genome walking approach. Computational predictions recognized typical gene features and protein motifs described for other plant β-1,3-glucanases. Phylogenetic reconstructions suggest strong support for evolutionary relatedness to class V β-1,3-glucanases, including homologs that are active in the traps of related carnivorous species. The gene is expressed in sundew vegetative tissues but not in flowers and digestive glands, and encodes for a functional enzyme when expressed in transgenic tobacco. Detailed analyses of the supposed promoter both in silico and in transgenic tobacco suggest that this glucanase plays a role in development. Specific spatiotemporal activity was observed during transgenic seed germination. Later during growth, the sundew promoter was active in marginal and sub-marginal areas of apical true leaf meristems of young tobacco plants. These results suggest that the isolated glucanase gene is regulated endogenously, possibly by auxin. This is the first report on a nuclear gene study from sundew.

Perception of biotech trees by Slovak university students – a comparative survey

Abstract Acceptance of genetically modified plants is restricted in EU by legislation, while the attitude of public is not favourable as well. Surveys show that knowledge about GM plants is getting increased. Newly developed strategies on GM safety for environment can be a crucial aspect for the (partial) acceptance in future. GM trees as non-edible plants might appear as more admissible, however, are relatively rarely discussed. We performed a comparative survey on knowledge and perception of GM forest trees among students at four Slovak universities. We also compared their responses between as well as with the outcome of similar cross-country survey in frames of the COST Action FP0905. The results point to very similar attitude of Slovak students when compared with students from other countries, no significant difference between responses of males and females, but also influence of age as well as orientation of their study (natural sciences vs. economy) on view of GM tree safety and placing on the market.