Tissue specific expression of β-glucuronidase gene driven by heterologous promoters in transgenic cauliflower plants

In this paper we compare five heterologous promoters fused to β-glucuronidase gene in their influence on localization of GUS activity in cauliflower (Brassica oleracea var. botrytis) tissues: roots, leaves, petioles and curds. A constitutive promoter CaMV 35S and four tissue specific promoters were used: extAP from rape, PsMTAP from pea, RBCS3CP from tomato and SRS1P from soybean, and introduced into cauliflower seedling explants using Agrobacterium rhizogenes mediated transformation. Quantitative and histochemical GUS assays confirmed tissue specific gus expression. It was found that extAP promoter was the most active in petioles but also caused a significant gus expression in curds. GUS activity was hardly observed in curd and restricted only to its epidermis when PsMTAP promoter drove the gene. RBCS3CP and SRS1P promoters controlled similar expression of the gus gene throughout the plant except for curd where RBCS3CP was almost inactive.     

Spatial heterogeneity of the species composition of a clavarioid fungi’s compex in the Eurasian Arctic

Using the example of a model group of macromycete (clavarioid fungi), a large-scale investigation into the mycological complex of the Eurasian Arctic is conducted. The species composition of clavarioid fungi’s complex is revealed in all longitudinal sectors and latitudinal subzones, and a comparative analysis is carried out. It has been determined that, among groups of aphyllophoroid fungi, the clavarioid life form is the most adapted to the extremally psychrophilic conditions of the Arctic. It is shown that the near-oceanic sectors are the richest, whereas the continental sectors are much poorer. The distribution of the species composition of fungi conforms to the similar distribution of flowering plants, especially hemicryptophytes. The average annual quantity of atmospheric precipitation is the leading climatic factor. The differences make it possible to subdivide the Eurasian Arctic into four mycogeographical regions: Atlantic (European), Siberian, Chukotian (Beringian), and High Arctic.     

‘Phytoantibodies’: a general vector for the expression of immunoglobulin domains in transgenic plants

Sequences encoding the immunoglobulin heavy-chain variable (VH) domains were engineered in a new general purpose vector to transform plants via Agrobacterium. The expression of an isolated VH domain (IVD) after introduction into the plant genome has been monitored by northern, western and immuno-histochemical analysis. Immunoblotting showed that the polypeptide was stably expressed and accounted for up to 1% of the soluble protein fraction. It is therefore proposed that single immunoglobulin domains of suitable specificity expressed in plants may constitute an effective system to inhibit the activity of molecules involved in plant pathology or plant development.     

Production of novel antioxidative phenolic amides through heterologous expression of the plant’s chlorogenic acid biosynthesis genes in yeast

Phenolic esters like chlorogenic acid play an important role in therapeutic properties of many plant extracts. We aimed to produce phenolic esters in baker’s yeast, by expressing tobacco 4CL and globe artichoke HCT. Indeed yeast produced phenolic esters. However, the primary product was identified as N-(E)-p-coumaroyl-3-hydroxyanthranilic acid by NMR. This compound is an amide condensation product of p-coumaric acid, which was supplied to the yeast, with 3-hydroxyanthranilic acid, which was unexpectedly recruited from the yeast metabolism by the HCT enzyme. N-(E)-p-coumaroyl-3-hydroxyanthranilic acid has not been described before, and it shows structural similarity to avenanthramides, a group of inflammation-inhibiting compounds present in oat. When applied to mouse fibroblasts, N-(E)-p-coumaroyl-3-hydroxyanthranilic acid induced a reduction of intracellular reactive oxygen species, indicating a potential therapeutic value for this novel compound.     

Effect of deletions 5′ to the translation initiation sequence on the expression of an mRNA in animal cells

To learn if an mRNA·18S rRNA interaction or a special secondary structure in the mRNA start region is essential for translation in eukaryotic cells, we constructed recombinant plasmids with the SV40 early promoter 5 to part of the Escherichia coli tuf B-lacZ gene. Deletion of bases potentially complementary to the 18S rRNA highly increased the transient -galactosidase expressed in transfected CHO cells. Deletion of bases that fostered formation of potential hairpins with the mRNA 5-terminus or altered the structure of the coding region reduced -galactosidase activity suggesting that these features of the mRNA secondary structure may be essential for initiation of translation. Computer aided analysis of the potential structure of 290 mRNAs suggests these are conserved features of the initiation region.     

The effect of a digital learning environment on children’s conceptions about the protection of endemic plants

This study presents the results of a pilot learning intervention for improving children’s ideas about plant protection. The research was executed in two phases. The first phase aimed at exploring children’s ideas about plant protection. These ideas were taken into account for the design and development of a digital learning environment. The second phase concerned the development, implementation and evaluation of the learning environment. In the first phase, 262 participants (10–12 years old) were asked to write a short text about ‘Environmental protection’. During the second phase, twenty-six participants (10–12 years old) were asked to write a text on ‘How we can protect the endemic plants’, before and after the implementation of the learning activities. Responses were content analysed and their meaning was classified according to the coding scheme of Blanchet-Cohen, Ragan, and Amsden (Children, Youth and Environments 2003; 13: 1–7). The results of the first phase showed that participants mentioned individual lifestyle actions of environmental protection and, therefore, the learning environment should emphasise the importance of other types of environmental protection (eg political actions, legislation, social actions). The proposed learning activities enriched participants’ awareness about the importance of social and legal actions for plant protection.     

The effect of glucose on the expression of a clonedBacillus amyloliquefaciens α-amylase gene in strains ofBacillus subtilis

Bacillus subtilis strain 1A297 was shown to relieve the glucose repression of a clonedB. amyloliquefaciens -amylase gene carried on the hybrid plasmid pVC102 without affecting its temporal activation. However, glucose repression of -amylase occurred when pVC102, was introduced intoB. subtilis strain 1A289. Glucose repression was relieved by -methyl-d-glucoside, an analog of glucose that blocks its uptake. The relief of glucose repression in 1A297 did not act at the level of plasmid copy number. As 1A297 was capable of exerting glucose repression on a homologous chromosomally encoded gene, it is postulated that the putativetrans-acting product involved in glucose repression inB. subtilis (Nicholson and Chambliss, 1986, J. Bacteriol. 165:663–670) is altered in strain 1A297 and does not recognize theB. amyloliquefaciens -amylase gene.     

Development of acetosyringone-inducible Gateway® and Golden Gate expression vectors for heterologous gene expression in Agrobacterium tumefaciens

In Vitro Cellular & Developmental Biology - Plant - As a plant genetic engineer, Agrobacterium tumefaciens utilizes phenolic compounds, such as acetosyringone, to activate its virulence genes...     

Isolation of the promoter of a cotton β-galactosidase gene (GhGal1) and its expression in transgenic tobacco plants

β-galactosidases (GUS, EC 3.2.1.23) are character- ized by their ability to hydrolyze terminal, non-re- ducing β-D-galactosyl residues from β-D-galactosides and are widely distributed in microbes, plants and animals. To date, the primary structures of …     

A study on the niches of the state’s key protected plants in Bawangling,Hainan Island

Aims An understanding on the living communities of the state’s key protected wild plants and the ability in utilizing resources and occupying ecological spaces by different populations is essential to the protection and propagation of rare and endangered plant species. We use our findings to highlight the knowledge gaps in the conservation strategies for the endangered species.
Methods Field investigations were conducted during 2009-2011. Based on the survey data on 70 forest plots in the Bawangling protected area, the niche breadths and overlaps of 12 species listed as the state’s key protected plants were calculated and analyzed.
Important findings The 12 species, by their niche breadth values in descending order, include Aquilaria sinensis, Nephelium topengii, Camellia sinensis var. assamica, Alseodaphne hainanensis, Keteleeria hainanensis, Podocarpus imbricatus, Firmiana hainanensis, Parakmeria lotungensis, Cephalotaxus mannii, Michelia hedyosperma, Ixonanthes reticulata, Dacrydium pierrei. The niche breadth value of a species is closely related to its range of geographical distribution; both Dacrydium pierrei and Parakmeria lotungensis had a narrow niche breadth corresponding to their narrow ranges of altitudinal distribution. In general, the niche overlap value is higher between species with greater niche breadth; the highest niche overlap value of 0.872 was found between Camellia sinensis var. assamica and Keteleeria hainanensis. However, the niche overlap value between species with smaller niche breadth could also be high; e.g. the niche overlap value was relatively high (0.693) between two species with smaller niche breadth, Michelia hedyosperma and Firmiana hainanensis, indicating that niche overlap value is dependent upon the biological characteristics and requirements for environmental resources of the species of comparison. Some species with low niche breadth values (e.g. Michelia hedyosperma and Ixonanthes reticulata) were found to have smaller populations. Due to lack of suitable community and habitats, these plant species are in dire need of more attention and prioritization for conservation. In conclusion, for the better protection and propagation of these endangered plants in the future, we should combine knowledge of their biological characteristics with that of their living communities such as the montane rainforests, etc.     

The 5′-untranslated region of the maize alcohol dehydrogenase gene provides efficient translation of mRNA in plants under stress conditions

The reduced level of expression of most cell proteins under stress conditions is determined by the low efficiency of cap-dependent translation of corresponding mRNAs. The maize gene encoding alcohol dehydrogenase, adh1, is a gene whose mRNA is efficiently translated in hypoxia. The reporter gene assay showed that the leader sequence of the adh1 mRNA provided for efficient translation of the reporter gfp gene in Nicotiana benthamiana cells in hypoxia or heat shock. The presence of this sequence in the 5′-UTR of mRNA did not change the level of expression under aerobic conditions, but the levels of gfp expression in hypoxia or heat shock were reduced five-to tenfold in the absence of this leader and remained unaffected when the adh leader sequence was present in the 5′-UTR. The adh1 leader sequence did not change the mRNA stability nor exhibited a promoter activity. Thus, the adh leader sequence acted as a translational enhancer, providing for efficient mRNA translation in plant cells under stress conditions. Introduction of this sequence into standard expression cassettes was proposed for the development of new systems to efficiently express the target proteins in plants under stress conditions.     

Multiple roles of the coding sequence 5′ end in gene expression regulation

The codon composition of the coding sequence''s (ORF) 5′ end first few dozen codons is known to be distinct to that of the rest of the ORF. Various explanations for the unusual codon distribution in this region have been proposed in recent years, and include, among others, novel regulatory mechanisms of translation initiation and elongation. However, due to the fact that many overlapping regulatory signals are suggested to be associated with this relatively short region, its research is challenging. Here, we review the currently known signals that appear in this region, the theories related to the way they regulate translation and affect the organismal fitness, and the debates they provoke.