An Oxidized Ergosterol from <Emphasis Type="Italic">Pleurotus cystidiosus</Emphasis> Active Against Anthracnose Causing <Emphasis Type="Italic">Colletotrichum</Emphasis><Emphasis Type="Italic">gloeosporioides</Emphasis>

This study was undertaken to study the antifungal activity of Pleurotus cystidiosus against Colletotrichum gloeosporioides. This was achieved by fractionating the mushroom, P. cystidiosus initially to acetone (A), dichloromethane (D), and hexane (H) and studying the antifungal activity using the standard poisoned food technique. All the test solutions used were in the concentration of 20,000 ppm. The percentage inhibition of extracts A, D, and H was 12, 7, and 0.4%, respectively. Antifungal assay guided fractionation of the most active extract A resulted in four fractions; A1, A2, A3, and A4 having 12, 22, 0, and 17% percentage inhibitions, respectively. Fractions A2 and A4 were selected for further purifications. Normal phase column chromatography of A2 gave A2-1, A2-2, A2-3, and A2-4, with percentage inhibitions 7, 5, 26, and 13%, respectively. The fraction with the highest inhibitory activity (A2-3) was further separated using the Chromatotron and a single compound (A2-3-13) with 41% inhibition was isolated. Structure elucidation of this compound using 1D and 2D NMR spectroscopy proved this compound to be 3beta, 5alpha, 6beta-trihydroxyergosta-7,22-diene.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

Morphological changes of <Emphasis Type="Italic">Fusarium</Emphasis><Emphasis Type="Italic">oxysporum</Emphasis> induced by CF66I,an antifungal compound from <Emphasis Type="Italic">Burkholderia cepacia</Emphasis>

The morphological effects of CF66I, an antifungal compound produced by Burkholderia cepacia, on growing hyphae of Fusarium oxysporum were studied by fluorescence microscopy (FM) and transmission electron microscopy (TEM). At 20 μg/ml, CF66I strongly inhibited growth and induced significant changes of the hyphal morphology. These changes included swelling of hyphae with considerable thickening cell wall and abnormal chitin deposition, which was indicative of the alterations in cell wall structure. Furthermore, fluorescein diacetate (FDA) staining indicated the loss of intracellular esterase activity. CF66I probably inhibits fungal growth by interfering with the cell metabolic pathways. At 120 μg/ml, CF66I killed F. oxysporum (accompanied by propidium iodide permeation, intracellular cytoplasm leakage and crushing of hyphal tips), probably by direct damage to the cell membrane. Thus, there are two different antifungal mechanisms of CF66I, depending on its concentration, and further studies on this compound might be useful for us to develop a new class of antifungal agents.     

Over-expressing a UDP-glucosyltransferase gene (<Emphasis Type="Italic">Ta-UGT</Emphasis><Subscript><Emphasis Type="Italic">3</Emphasis></Subscript>) enhances <Emphasis Type="Italic">Fusarium</Emphasis> Head Blight resistance of wheat

Wheat Fusarium Head Blight (FHB), mainly caused by Fusarium graminearum (F.g), is a destructive fungal disease worldwide. FHB can not only cause considerable reduction in yield, but more seriously, can contaminate grain by trichothecene toxins released by the fungus. Here, we report new insights into the function and underlying mechanisms of a UDP-glycosyltransferase gene, Ta-UGT ₃ , that is involved in FHB resistance in wheat. In our previous study, Ta-UGT ₃ was found to enhance host tolerance against deoxynivalenol (DON) in Arabidopsis. In this study, four transgenic lines over-expressing Ta-UGT ₃ in a FHB highly susceptible wheat variety, Alondra’s, were obtained and characterized. 3 years of assays using single floret inoculation with F.g indicated that all four transgenic lines exhibited significantly enhanced type II resistance to FHB and less DON accumulation in the grains compared to the untransformed control. Histological observation using GFP labelled F.g was in agreement with the above test results since over-expression of Ta-UGT ₃ dramatically inhibited expansion of F.g. To explore the putative mechanism of resistance mediated by Ta-UGT ₃ , microarray analysis, qRT-PCR and hormone measurements were performed. Microarray analysis showed that DON up-regulated genes, such as TaNPR1, in the susceptible control, and down-regulated genes in F.g inoculated transgenic lines, while qRT-PCR showed that some defence related genes were up-regulated in F.g inoculated transgenic lines. Ta-UGT ₃ over-expression also changed the contents of the endogenous hormones SA and JA in the spikes. These data suggest that Ta-UGT ₃ positively regulates the defence responses to F.g, perhaps by regulating defence-related and DON-induced downstream genes.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

The tyrosine <Emphasis Type="Italic">O</Emphasis>-prenyltransferase SirD catalyzes <Emphasis Type="Italic">O</Emphasis>-, <Emphasis Type="Italic">N</Emphasis>-, and <Emphasis Type="Italic">C</Emphasis>-prenylations

Recently, the prenyltransferase SirD was found to be responsible for the O-prenylation of tyrosine in the biosynthesis of sirodesmin PL in Leptosphaeria maculans. In this study, the behavior of SirD towards phenylalanine/tyrosine and tryptophan derivatives was investigated. Product formation has been observed with 12 of 19 phenylalanine/tyrosine derivatives. It was shown that the alanine structure attached to the benzene ring and an electron donor, e.g., OH or NH₂, at its para-position are essential for the enzyme activity. Modifications were possible both at the side chain and the benzene ring. Enzyme products from seven phenylalanine/tyrosine derivatives were isolated and characterized by MS and NMR analyses including HSQC and HMBC and proven to be O- or N-prenylated derivatives at position C4 of the benzene rings. K _M values of six selected derivatives were found in the range of 0.10–0.68 mM. Catalytic efficiencies (K _cat/K _M ) were determined in the range of 430–1,110 s⁻¹·M⁻¹ with l-tyrosine as the best substrate. In addition, 7 of 14 tested tryptophan analogs were also accepted by SirD and converted to C7-prenylated derivatives, which was confirmed by comparison with products obtained from enzyme assays using a 7-dimethylallyltryptophan synthase 7-DMATS from Aspergillus fumigatus.     

New combinations and typifications in <Emphasis Type="Italic">Bistorta</Emphasis>, <Emphasis Type="Italic">Persicaria</Emphasis>, <Emphasis Type="Italic">Polygonum,</Emphasis> and <Emphasis Type="Italic">Rumex</Emphasis> (Polygonaceae)

New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.     

The <Emphasis Type="Italic">Caenorhabditis</Emphasis><Emphasis Type="Italic">briggsae</Emphasis> genome contains active <Emphasis Type="Italic">CbmaT1</Emphasis> and <Emphasis Type="Italic">Tcb1</Emphasis> transposons

The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.     

A new methanol assimilating yeast, <Emphasis Type="Italic">Ogataea</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>, the ascosporic state of <Emphasis Type="Italic">Candida</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>

Ogataea parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea angusta and Ogataea polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica.     

Prevalence,intensity and associated factor analysis of <Emphasis Type="Italic">Tropilaelaps</Emphasis><Emphasis Type="Italic">mercedesae</Emphasis> infesting <Emphasis Type="Italic">Apis</Emphasis><Emphasis Type="Italic">mellifera</Emphasis> in China

Tropilaelaps mercedesae is a serious ectoparasite of Apis mellifera in China. The aim of this study was to investigate the infestation rates and intensity of T. mercedesae in A. mellifera in China, and to explore the relative importance of climate, district, management practices and beekeeper characteristics that are assumed to be associated with the intensity of T. mercedesae. Of the 410 participating apiaries, 379 apiaries were included in analyses of seasonal infestation rates and 352 apiaries were included in multivariable regression analysis. The highest infestation rate (86.3%) of T. mercedesae was encountered in autumn, followed by summer (66.5%), spring (17.2%) and winter (14.8%). In autumn, 28.9% (93) of the infested apiaries were in the north (including the northeast and northwest of China), 71.1% (229) were in the central and south (including east, southeast and southwest China), and 306 apiaries (82.9%) were co-infested by both T. mercedesae and Varroa. Multivariable regression analysis showed that geographical location, season, royal jelly collection and Varroa infestation were the factors that influence the intensity of T. mercedesae. The influence of beekeeper’s education, time of beekeeping, operation size, and hive migration on the intensity of T. mercedesa was not statistically significant. This study provided information about the establishment of the linkage of the environment and the parasite and could lead to better timing and methods of control.     

In planta transformation of <Emphasis Type="Italic">Notocactus scopa</Emphasis> cv. <Emphasis Type="Italic">Soonjung</Emphasis> by <Emphasis Type="Italic">Agrobacterium </Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>

Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species.     

Nivalenol production by<Emphasis Type="Italic">Fusarium poae</Emphasis>

Fusarium sp. were isolated from Swedish nivalenol containing grain and tested for toxin production. OnlyF. poae, 6 of 10 isolates, produced nivalenol. Highest production (44.7 μg/g) was obtained cultured on rice during 4 week at room temperature and under near UV-light. FiveF. poae isolates from other countries did not produce nivalenol but T-2/HT-2 toxin. One Swedish isolate produced both types of trichothecenes. Treatment with fungicides in aF. poae infected experimental field reduced the nivalenol concentration in the harvested grain.     

<Emphasis Type="Italic">Fusarium</Emphasis> Infection Causes Phenolic Accumulations and Hormonal Disorders in <Emphasis Type="Italic">Orobanche</Emphasis> spp.

The physiological effects of Fusarium oxysporum on in-root parasitic weed, Orobanche spp. (broomrape) with references to change in plant hormones and secondary plant constituents were investigated. The levels of IAA, GA, ABA and JA in the experimental group were significantly lower than those in the control group, while the level of SA was higher in the experimental group. In secondary metabolic studies, the quantities of various phenols were measured in the two groups and catechin, syringic acid and p-coumaric acid amounts were significantly higher in the experimental group than in the control group, unlike gallic acid which have a lower amount. Consequently, in the light of all data, it was concluded that Fusarium oxysporum (1) causes heavy hormonal disorder, (2) triggered only SA-mediated defense and (3) induced intensively accumulation of phenolic substances in orobanche. Fusarium oxysporum causes lethal physiological damage on Orobanche spp.