Study on metal-triggered callose deposition in roots of maize and soybean

Abstract: Callose plays important roles in a variety of processes of plant development, and/or in a response to a range of biotic and abiotic stresses. In the current work we have studied and compared the effect of lead, cadmium and arsenic on accumulation of newly formed callose deposits in the roots of maize and soybean. We observed formation of characteristic callose deposits in the root cell walls, probably associated with plasmodesmata, depending on the type of metal and the plant species investigated. Further, the callose turnover was analysed by measuring of total callose content as well as activities of total β-(1,3)-glucanases in roots. The latter enzymes are responsible for callose depletion, and their possible role during metal stress has previously been proposed. However, neither of these biochemical values appeared to be sufficiently reliable for scoring the altered callose turnover (including local deposits) in plant tissue. The microscopical observations are discussed in light of the biochemical data obtained

Optimization of Plant Extract Purification Procedure for Rapid Screening Analysis of Sixteen Phenolics by Liquid Chromatography

A solid-phase extraction (SPE) procedure was developed for simultaneous monitoring of sixteen different phenolics of various polarity, quantified by high-performance liquid chromatography (HPLC). The procedure allowed screening the accumulation of intermediates in different metabolic pathways that play a crucial role in plant physiology and/or are beneficial for human health. Metabolites mostly involved in phenylpropanoid, shikimate, and polyketide pathways comprise chlorogenic acid, gentisic acid, vanillic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, quercetin, epicatechin, gallic acid, sinapic acid, p-coumaric acid, o-coumaric acid, vanillin; two rarely quantified metabolites, 2,5-dimethoxybenzoic acid and 4-methoxycinnamic acid, were included as well. The procedure offered low cost, good overall efficiency, and applicability in laboratories with standard laboratory equipment. SPE recoveries were up to 99.8% at various concentration levels. The method allowed for routine analysis of compounds with a wide range of polarity within a single run, while its applicability was demonstrated for various model plant species (tobacco, wheat, and soybean), as well as different tissue types (shoots and roots)

Optimization of Plant Extract Purification Procedure for Rapid Screening Analysis of Sixteen Phenolics by Liquid Chromatography

A solid-phase extraction (SPE) procedure was developed for simultaneous monitoring of sixteen different phenolics of various polarity, quantified by high-performance liquid chromatography (HPLC). The procedure allowed screening the accumulation of intermediates in different metabolic pathways that play a crucial role in plant physiology and/or are beneficial for human health. Metabolites mostly involved in phenylpropanoid, shikimate, and polyketide pathways comprise chlorogenic acid, gentisic acid, vanillic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, quercetin, epicatechin, gallic acid, sinapic acid, p-coumaric acid, o-coumaric acid, vanillin; two rarely quantified metabolites, 2,5-dimethoxybenzoic acid and 4-methoxycinnamic acid, were included as well. The procedure offered low cost, good overall efficiency, and applicability in laboratories with standard laboratory equipment. SPE recoveries were up to 99.8% at various concentration levels. The method allowed for routine analysis of compounds with a wide range of polarity within a single run, while its applicability was demonstrated for various model plant species (tobacco, wheat, and soybean), as well as different tissue types (shoots and roots)

Metabolické a oxidační změny v kapradině Adiantum raddianum po aplikaci kovů

Cadmium (Cd) or nickel (Ni) were applied as a foliar spray (1 µM solution over one month) to mimic air pollution and to monitor metabolic responses and oxidative stress in the pteridophyte species. Exogenous metals did not affect the metal content of the soil and had relatively little effect on the essential elements in leaves or rhizomes. The amounts of Cd and Ni were similar in treated leaves (7.2 µg Cd or 5.3 µg Ni/g DW in mature leaves compared with 0.4 µg Cd or 1.2 µg Ni/g DW in the respective control leaves), but Ni was more abundant in rhizomes (56.6 µg Ni or 3.4 µg Cd/g DW), resulting in a higher Cd translocation and bioaccumulation factor. The theoretical calculation revealed that ca. 4% of Cd and 5.5% of Ni from the applied solution per plant/pot was absorbed. Excess Cd induced stronger ROS production followed by changes in SOD and CAT activities, whereas nitric oxide (NO) stimulation was less intense, as detected by confocal microscopy. The hadrocentric vascular bundles in the petioles also showed higher ROS and NO signals under metal excess. This may be a sign of increased ROS formation, and high correlations were observed. Proteins and amino acids were stimulated by Cd or Ni application in individual organs, whereas phenols and flavonols were almost unaffected. The data suggest that even low levels of exogenous metals induce an oxidative imbalance, although no visible damage is observed, and that the responses of ferns to metals are similar to those of seed plants or algae.Studie byla věnována identifikaci specifických změn v kapradinách Adiantum raddianum s ohledem na akumulaci kovů a biochemické změny, po dlouhodobé exogenní expozici nízkými koncentracemi Cd a Ni

Variable dynamics of cadmium uptake and allocation in four soybean cultivars

Cadmium is a serious environmental pollutant and its uptake by plant represents a serious health risk. Uptake, accumulation as well as sensitivity of soybean plants to metals have been shown to vary with genotype, while the dynamics of this uptake has rarely been studied. Here we studied the uptake and accumulation of Cd2+ ions in different parts of soybean plants of four cultivars Moravians, Gallec, Kent and Cardiff. The plants at early developmental stage were immersed in Hoagland nutrient solution in the presence or absence of 50 mg.L−1 and the isotope of 109Cd2+ to monitor its accumulation continuously at 24 h intervals for 10 days. Our results showed that the uptake rate varied among the cultivars, being the highest in roots of the cv. Moravians and the lowest in the cv. Gallec. We also observed a non-even distribution of radioactivity within the entire plants of individual cultivars. The most of Cd2+ isotope was translocated into primary leaves and leaves in the cvs. Kent and Moravians; on the contrary, relatively less in the cvs. Cardiff and Gallec. The results were fitted with genetic potential, growth as well as defense parameters such as proline accumulation. Combining uptake dynamics and biochemical data are indicative for different tolerance strategies of soybeans

Changes in Soluble Protein Profile in Cotton Leaves Indicate Rubisco Damage after Treatment with Sumi-Alpha Insecticide

The cotton plant suffers from many pests and due to its economic importance, the use of efficient but ecologically friendly pesticides is highly desirable. The insecticide Sumi-Alpha with active compound Esfenvalerate is widely used for cotton treatment in Uzbekistan. This insecticide is considered as moderately hazardous for different organisms of ecosystems, while more collected data and relevant research is a necessity for judgement of their safety and/or potential risk. Therefore, a comparative analysis of cotton leaves was performed to study the protein profile changes upon treatment with this insecticide. Our data showed elevated accumulation of fructose bisphosphate aldolase and degradation of RuBisCo in the treated tissue. Besides, a protein belonging to P-loop containing nucleoside triphosphate hydrolases superfamily exerted lower accumulation. Our results indicate that the applied pyrethroid pesticide possibly can affect photosynthesis performance and cause accumulation of simple saccharides which in turn might contribute to enhanced colonisation of sucking insects. Further molecular research on Sumi-Alpha effects on cotton is necessary for its safer use in agricultural practice

Introduction of a synthetic Thermococcus-derived α-amlyase gene into barley genome for increased enzyme thermostability in grains

Background: The enzymes utilized in the process of beer production are generally sensitive to higher temperatures. About 60% of them are deactivated in drying the malt that limits the utilization of starting material in the fermentation process. Gene transfer from thermophilic bacteria is a promising tool for producing barley grains harboring thermotolerant enzymes. Results: Gene for α-amylase from hydrothermal Thermococcus, optimally active at 75–85°C and pH between 5.0 and 5.5, was adapted in silico to barley codon usage. The corresponding sequence was put under control of the endosperm-specific promoter 1Dx5 and after synthesis and cloning transferred into barley by biolistics. In addition to model cultivar Golden Promise we transformed three Slovak barley cultivars Pribina, Levan and Nitran, and transgenic plants were obtained. Expression of the ~50 kDa active recombinant enzyme in grains of cvs. Pribina and Nitran resulted in retaining up to 9.39% of enzyme activity upon heating to 75°C, which is more than 4 times higher compared to non-transgenic controls. In the model cv. Golden Promise the grain α-amylase activity upon heating was above 9% either, however, the effects of the introduced enzyme were less pronounced (only 1.22 fold difference compared with non-transgenic barley). Conclusions: Expression of the synthetic gene in barley enhanced the residual α-amylase activity in grains at high temperatures. Keywords: Amylopectin, Amylose, Beer, Fermentation, Gene transfer, Glutenin, Hordeum, Promoter, Seed-directed expression, Synthetic gene, Thermotolerant bacteri

In Vitro Regeneration Potential of Seven Commercial Soybean Cultivars (Glycine max L.) for Use in Biotechnology

This work is aimed to evaluate in vitro regeneration potential of seven commercial soybean varieties Bohemians, Cardiff, Gallec, Merlin, Moravians, Naya and Silensia (Glycine max L.) cultivated in Central Europe. Our results showed the half-seeds could be effectively used as an explant source for all tested cultivars. The regeneration was initiated on the media containing growth regulators 1.67 mg.l-1 BAP and 0.25 mg.l-1 GA3. Within the first five days culture, green chlorophyll-containing explants were observed with frequency from 18.3% to 55.9%. Two weeks later, the explants responded by production of calli with the efficiency up to 83.0%. First shoots appeared after 2–3 weeks of subculture on the media. The soybean regeneration showed to be genotype-dependent with variable efficiencies from 5.7% (cv. Naya) to 37.7% (cv. Gallec). The cultivars Cardiff, Merlin and Gallec appear to be the most promising candidates for further biotechnological use. Application of antioxidants such as L-cysteine, dithiothreitol and sodium thiosulfate does not have effect on the explant regeneration for the first five days

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

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