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The lucerne seed web moth or etiella moth, Etiella behrii (Zeller) (Lepidoptera: Pyralidae: Phycitinae: Phycitini) has been recorded as adults and larvae across mainland Australia on leguminous plants. Suitable host plants occur in Tasmania but detections are restricted to adults, mostly in one long-term light trap. A combination of methods is used to determine whether this pest is a non-breeding vagrant, a breeding migrant or resident in Tasmania. A degree-day development model for E. behrii showed that warmer source areas outside Tasmania better explained flight seasonality observed by light trapping in Tasmania than local source areas. Pest records of 119 Lepidoptera associated with Tasmanian Medicago plants do not include Etiella . The absence of records of larvae, the coincidence of adults with migratory insects and northerly airflows, flight seasonality and a requirement for a six month non-developmental period in the cool season indicate that E. behrii migrates to Tasmania where any breeding is below detection although two generations seem possible based on thermal requirements. The results provide another example of a pest that fails to establish, even ephemerally, in Tasmania despite repeated migration from mainland Australia. The precise impediments to seasonal establishment of E. behrii remain unclear but this would most likely occur in north-west or north-east Tasmania, which receive most migratory moths. E. behrii is one of a suite of native Australian pests that may extend its breeding range to Tasmania with global warming. Climate matching models are prone to error if they assume E. behrii is resident in Tasmania. [ABSTRACT FROM AUTHOR]

Adults but not nymphs of green mirid, Creontiades dilutus (Stål) (Hemiptera: Miridae) are sometimes detected in Tasmania. The species has been recorded, as adults at least, from a wide range of habitats, localities and plants in mainland Australia and suitable host plants occur in Tasmania. Most Tasmanian detections of C. dilutus have been in a long-term light trap and coincide with movements of known long-distance migratory insects and airflows favourable for migration across Bass Strait. In contrast adults and juveniles of the potato bug Closterotomus norwegicus (Gmelin) (Hemiptera: Miridae) are collected regularly in crops for which details are given. A published degree-day development model for C. dilutus was used to identify several impediments to fecundity, egg and juvenile survival and adult maturation such that even ephemeral seasonal establishment is highly unlikely. The absence of juveniles, coincidence of adults with migratory insects and northerly airflows and modelled obstacles to breeding in combination indicate that C. dilutus migrates to Tasmania. The results provide another example of a pest that fails to establish, even ephemerally, in Tasmania despite repeated migration from mainland Australia. Publications stating that the distribution of C. dilutus includes Tasmania are based only on captures of migratory adults. Climate matching models are prone to error if they assume C. dilutus is resident in Tasmania. [ABSTRACT FROM AUTHOR]

Abstract: Chlorogenic acid (CGA) is one of the most abundant phenolic compounds in tomato (Solanum lycopersicum). Hydroxycinnamoyl CoA quinate transferase (HQT) is the key enzyme catalysing CGA biosynthesis in tomato. We have studied the relationship between phenolic accumulation and UV-susceptibility in transgenic tomato plants with altered HQT expression. Overall, increased CGA accumulation was associated with increased UV-protection. However, the genetic manipulation of HQT expression also resulted in more complex alterations in the profiles of phenolics. Levels of rutin were relatively high in both HQT gene-silenced and HQT-overexpressing plants raised in plant growth tunnels. This suggests plasticity in the flux along different branches of phenylpropanoid metabolism and the existence of regulatory mechanisms that direct the flow of phenolic precursors in response to both metabolic parameters and environmental conditions. These changes in composition of the phenolic pool affected the relative levels of UV-tolerance. We conclude that the capability of the phenolic compounds to protect against potentially harmful UV radiation is determined both by the total levels of phenolics that accumulate in leaves as well as by the specific composition of the phenolic profile. [Copyright &y& Elsevier]

The non-pathogenic, non-glycopeptide-producing actinomycete Streptomyces coelicolor carries a cluster of seven genes (vanSRJKHAX) that confers inducible, high level resistance to vancomycin. The vanK gene has no counterpart in previously characterized vancomycin resistance clusters, yet vanK is required for vancomycin resistance in S. coelicolor. YanK belongs to the Fem family of enzymes, which add the branch amino acid(s) to the stem pentapeptide of peptidoglycan precursors. Upon exposure to vancomycin, the VanRS two-component system switches on expression of all seven van genes, and the VanHAX enzymes reprogram the cell wall such that precursors terminate D-Ala-D-lactate (Lac) rather then D-Ala-D-Ala, thus conferring resistance to vancomycin, which only binds D-Ala-D-Ala-containing precursors. Here we provide biochemical and genetic evidence that VanK is required for vancomycin resistance because the constitutively expressed FemX enzyme, encoded elsewhere on the chromosome, cannot recognize D-Lac-containing precursors as a sabstrate, whereas VanK can. Consistent with this view, D-Lac-containing precursors carrying the Gly branch are present in the wild type transiently exposed to vancomycin but are undetectable in a vanK mutant treated in the same way. Further, femX null mutants are viable in the presence of vancomycin but die in its absence. Because only VanK can recognize D-Lac-containing precursors, vancomycin-induced expression of VanHAX in a vanK mutant is lethal, and so vanK is required for vancomycin resistance. [ABSTRACT FROM AUTHOR]

The 6-deoxy sugar L-rhamnose (L-Rha) is found widely in plant and microbial polysaccharides and natural products. The importance of this and related compounds in host-pathogen interactions often means that L-Rha plays an essential role in many organisms. L-Rha is most commonly biosynthesized as the activated sugar-nucleotide uridine 5'-diphospho-β-L-rhamnose (UDP-β-L-Rha) or thymidine 5'-diphospho-β-L-rhamnose (TDP-β-L-Rha). Enzymes involved in the biosynthesis of these sugar nucleotides have been studied in some detail in bacteria and plants, but the activated form of L-Rha and the corresponding biosynthetic enzymes have yet to be explored in algae. Here, using sugar-nucleotide profiling in two representative algae, Euglena gracilis and the toxin-producing microalga Prymnesium parvum, we show that levels of UDP- and TDP-activated L-Rha differ significantly between these two algal species. Using bioinformatics and biochemical methods, we identified and characterized a fusion of the RmlC and RmlD proteins, two bacteria-like enzymes involved in TDP-β-L-Rha biosynthesis, from P. parvum. Using this new sequence and also others, we explored L-Rha biosynthesis among algae, finding that although most algae contain sequences orthologous to plant-like L-Rha biosynthesis machineries, instances of the RmlC-RmlD fusion protein identified here exist across the Haptophyta and Gymnodiniaceae families of microalgae. On the basis of these findings, we propose potential routes for the evolution of nucleoside diphosphate β-L-Rha (NDP-β-L-Rha) pathways among algae. [ABSTRACT FROM AUTHOR]

Abstract: In connection with prospective 18F-PET imaging studies, the potential for enzymatic synthesis of fluorine-labelled glycosides of small molecules was investigated. Approaches to the enzymatic synthesis of anomeric phosphates of d-gluco-configured fluorosugars proved ineffective. In contrast, starting in the d-galacto series and relying on the consecutive action of Escherichia coli galactokinase (GalK), galactose-1-phosphate uridylyltransferase (GalPUT), uridine-5′-diphosphogalactose 4-epimerase (GalE) and oat root glucosyltransferase (SAD10), a quick and effective synthesis of 6-deoxy-6-fluoro-d-glucosyl N-methylanthranilate ester was achieved. [Copyright &y& Elsevier]

Abstract: 2-Deoxy-2-fluoro-d-glucose, 3-deoxy-3-fluoro-d-glucose and 6-deoxy-6-fluoro-d-glucose were converted into the corresponding maltose derivatives using Arabidopsis thaliana DPE2-mediated trans-glycosylation reaction with glycogen acting as a glucosyl donor. 19F NMR spectroscopy proved to be a valuable tool for monitoring the progress of these reactions and to assess the nature of resulting oligomeric products. [Copyright &y& Elsevier]

Abstract: A new series of water-soluble tetravalent glycoclusters incorporating β-lactosyl residues attached to a central calix[4]arene core was synthesised using azide–alkyne Cu(I)-catalysed cycloaddition (‘click chemistry’). Carbohydrate moieties were attached either to the upper or lower rim of rigid cone-shaped or partial cone macrocycles via 14–21 atom spacer arms. The glycoclusters with a C4-symmetrical arrangement of β-lactosyl residues showed trypanocidal activity, with one of them showing comparable activity to established anti-trypanosomal drug benznidazole in in vitro anti-parasite assays. [Copyright &y& Elsevier]

Abstract: Trypanosoma cruzi trans-sialidase (TcTS) plays a key role in the recognition and invasion of host cells and in enabling the parasite to escape the human immune response. To explore this potential drug target, we have synthesized a small library of substrate analogues based on 1,4-disubstituted 1,2,3-triazole derivatives of galactose modified at either the C-1 or C-6 positions. This was achieved by coupling the appropriate azido-sugars with a panel of 23 structurally diverse terminal alkynes by using the copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction, giving a library of 46 derivatives in good to excellent yield and with complete regioselectivity. The sugar triazoles showed weak inhibition towards TcTS-catalyzed hydrolysis of 2′-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid in vitro (<40% inhibition at 1mM concentration); many of the compounds assessed proved to be acceptor substrates for the enzyme. Despite this modest inhibitory activity, in vitro trypanocidal activity assays against the trypomastigote form of T. cruzi Y strain revealed several compounds active in the low 100s of μM range. Further assessment of these compounds against cultured mouse spleen cells suggests a specific mode of anti-parasite action rather than a generic cytotoxic effect. [Copyright &y& Elsevier]

During the last years halogenated compounds have drawn a lot of attention. Metabolites with one or more halogen atoms are often more active than their non-halogenated derivatives like indole-3-acetic acid (IAA) and 4-Cl-IAA. Within this work, bacterial flavin-dependent tryptophan halogenase genes were inserted into Brassica rapa ssp. pekinensis (Chinese cabbage) with the aim to produce novel halogenated indole compounds. It was investigated which tryptophan-derived indole metabolites, such as indole glucosinolates or potential degradation products can be synthesized by the transgenic root cultures. In vivo and in vitro activity of halogenases heterologously produced was shown and the production of chlorinated tryptophan in transgenic root lines was confirmed. Furthermore, chlorinated indole-3-acetonitrile (Cl-IAN) was detected. Other tryptophan-derived indole metabolites, such as IAA or indole glucosinolates were not found in the transgenic roots in a chlorinated form. The influence of altered growth conditions on the amount of produced chlorinated compounds was evaluated. We found an increase in Cl-IAN production at low temperatures (8 °C), but otherwise no significant changes were observed. Furthermore, we were able to regenerate the wild type and transgenic root cultures to adult plants, of which the latter still produced chlorinated metabolites. Therefore, we conclude that the genetic information had been stably integrated. The transgenic plants showed a slightly altered phenotype compared to plants grown from seeds since they also still expressed the rol genes. By this approach we were able to generate various stably transformed plant materials from which it was possible to isolate chlorinated tryptophan and Cl-IAN. Brassica rapa has been transformed into transgenic root cultures harboring three different tryptophan-dependent halogenases from bacterial origin. These were regenerated to plants that stably contained the halogenase genes. Tryptophan was converted to Cl-tryptophan in planta and to other chlorinated indole derivatives by the plant enzymes. Image 1 • Hairy roots of Chinese cabbage were stably transformed with bacterial halogenase genes. • Halogenated tryptophan and compounds derived from the amino acid were found. • Production of halogenated compounds was induced by cold treatment. • Transgenic root cultures were regenerated to adult plants that stably contained the halogenase genes. • Regenerated plants produced the same set of halogenated metabolites as their progenitor. [ABSTRACT FROM AUTHOR]

The shelf-life of tomato ( Solanum lycopersicum ) fruit is determined by the processes of over-ripening and susceptibility to pathogens. Post-harvest shelf life is one of the most important traits for commercially grown tomatoes. We compared the shelf life of tomato fruit that accumulate different flavonoids and found that delayed over-ripening is associated with increased total antioxidant capacity caused by the accumulation of flavonoids in the fruit. However, reduced susceptibility to Botrytis cinerea , a major post-harvest fungal pathogen of tomato, is conferred by specific flavonoids only. We demonstrate an association between flavonoid structure, selective scavenging ability for different free radicals and reduced susceptibility to B. cinerea . Our study provides mechanistic insight into how flavonoids influence shelf life of tomato, information which could be used to improve the shelf life of tomato, and potentially of other soft fruit. [ABSTRACT FROM AUTHOR]