This study aimed to determine whether powdery mildew caused by Blumeria graminis is an endemic pathogen of triticale (×Triticosecale: Triticum × Secale), emerging as a result of recent changes in its ...pathogenicity, or whether it is a new pathogen, possibly resulting from hybridization between ff. spp. tritici and secalis. A secondary aim was to consider breeding practices that may have favoured this emergence. Phylogenetic analyses based upon six genes revealed the close relatedness of the novel entity and the ff. spp. tritici and secalis, but the IGS marker finally grouped together the isolates collected on triticale and on wheat, supporting the scenario of a recent host-range expansion from wheat to triticale. Pathotype analyses concluded that virulence spectra of B. graminis infecting triticale were new in comparison to those observed for other reference formae speciales, and lack of fungicide resistance in triticale isolates strengthens the hypothesis of no or little genetic exchange between wheat and triticale populations of powdery mildew. This adaptation may follow the breakdown of plant resistance genes, which are probably not very diverse in current triticale cultivars since this criterion was not considered as a major one until recent years. Moreover, the complex selection and genetics of this hybrid cereal makes it difficult to predict the transmission of powdery mildew resistance genes.
A microwave-assisted three-component, regioselective one-pot synthesis of spiroindole-thiazolidinones (
6a–
l) is carried out using montmorillonite KSF as solid support.
A microwave-assisted ...three-component, regioselective one-pot cyclocondensation method has been developed for the synthesis of a series of novel spiroindole-thiazolidinones (
6a–
l) using an environmentally benign procedure at atmospheric pressure in open vessel. This rapid method produces pure products in high yields within few minutes in comparison to a conventional two-step procedure. The crystal structure of one representative compound has been determined by X-ray diffraction. The synthesized compounds have been screened ‘in vitro’ for antifungal activity against
Rhizoctonia solani,
Fusarium oxysporum and
Collectotrichum capsici. All compounds have shown good activity against these pathogens.
L'objet de cet article est de présenter deux outils statistiques permettant de comparer deux techniques entre elles, mais surtout de proposer une interprétation correcte des résultats. L'un des ...outils repose sur la détermination d'une relation linéaire entre les deux techniques et la vérification de certaines conditions ; l'autre repose sur la réalisation d'un test statistique.
In this paper we propose a correct interpretation of two statistical tools used to compare two techniques.
In connection with a total synthesis of cephalotaxine (1a), we have examined the addition of various nucleophilic reagents to ABC subunits 2 and 7 possessing a pyrrolobenzazepine core. In fact, this ...reaction implicates invariably the carbonyl group of 2. Regarding the reaction of 7 with nucleophiles, the most striking aspect is the complete lack of reactivity of the enaminonitrile moiety. For instance, the condensation of 7 with methylmagnesium bromide involves exclusively the cleavage of the dioxole ring, yielding regioisomers 9 and 10. With the aim of understanding the unexpected reactivity of 2 and 7 toward nucleophiles, crystallographic studies of 2 and 7 and an experimental electron density determination of 7 were carried out. The marked reactivity of the carbonyl group of 2 was interpreted by invoking the weakness of the amide resonance, due to a pronounced delocalization of the N9 lone pair over the enaminonitrile moiety. The electron density study of 7 reveals this electron delocalization along the enaminonitrile fragment, highlighted and quantified through the bond geometries, topological indicators, and atomic charges, a phenomenon that is responsible for the failure of the addition of nucleophilic species.
Platinum is well known for its anticancer activity, firstly used as cis-diaminedichloroplatinum (II) (CDDP), with a wide range of activity. Its main mechanism of action involves its binding to DNA. ...Gallium, another metal, has also demonstrated apoptotic effects on malignant cells, but through interaction with targets other than DNA, such as the membrane, cytoskeleton and proteasome, and on enzyme activities. An antitumor synergism between CDDP and both gallium and rhenium compounds has been demonstrated. For these reasons, we proposed to combine these three metals and to determine at which doses each compound could be administered without major toxicity. CDDP, tetrakis(1-octanol) tris(5-aminosalicylate)gallium(III), and a diseleno-ether rhenium(I) complex were used in this experimental study in breast cancer MCF-7 tumor-bearing mice. CDDP was administered intraperitoneally (i.p.) twice a week at the dose of 3 mg/kg. Tetrakis(1-octanol) tris(5-aminosalicylate) gallium (III) and rhenium(I) diseleno-ether complexes were administered orally, daily, five days a week for three weeks, at doses ranging from 20 to 100 mg/kg for the gallium compound and from 10 to 50 mg/kg for the rhenium compound. Doses of 10 mg/kg of rhenium(I) diseleno-ether, and 100 mg/kg of the salicylate gallium compound, in combination with CDDP induced a significant decrease of 50% of the tumor volume, by comparison with the control group. In contrast, the decrease of the tumor volume in mice treated by CDDP alone was less than 25%. Changes in the sequence of administration of the three metals will be discussed to improve the therapeutic index.
The synthesis and characterization of three complexes with a potent nonsteroidal anti-inflammatory drug niflumic acid {2-3-(trifluoromethyl)phenylaminonicotinic acid} with formula Cu(niflumato)
2L ...(L=H
2O, DMSO=dimethylsulfoxide, DMF=
N,
N-dimethylformamide) were investigated. The crystal and molecular structure of the {Cu(niflumato)
2(DMSO)}
2 was reported. Crystallographic data are as follows: monoclinic system, space group
P2
1/
n,
Z=2,
a=11.1318(8),
b=17.513(2),
c=15.336(1) Å,
β=103.316(8)°,
V=2909.4(4) Å
3. The structure was refined to
R=0.030 and
w
R=0.037 for 3702 reflections with
I>
σ(
I). It consists of centrosymmetric binuclear units with the Cu–Cu
i (symmetry code i: 1−
x, −
y, 1−
z) distance between two centrosymmetrically related ions of 2.6272(5) Å. Each Cu(II) ion in Cu
2(DMSO)
2(μ-niflumato)
4 is coordinated to an apical dimethylsulfoxide O atom on the one hand and to the equatorial carbonyl and carboxylic O atoms of two crystallographically independent niflumate moieties and their centrosymmetric counterparts on the other hand. In spite of the low-temperature (190 K) crystal measurements, one –CF
3 grouping exhibits some disorder. The biological activities of these complexes were compared to that of niflumic acid. Niflumic acid and its various copper complexes significantly inhibited polymorphonuclear leukocyte (PMNL) oxidative metabolism, as assessed by chemiluminescence and
O
−
2
generation measurement. This effect was dose-dependent. All copper complexes exerted a similar inhibiting effect which was always significantly higher than that exerted by the parent drug.
Mature grapevine berries at the harvesting stage (MB) are very susceptible to the gray mold fungus Botrytis cinerea, while veraison berries (VB) are not. We conducted simultaneous microscopic and ...transcriptomic analyses of the pathogen and the host to investigate the infection process developed by B. cinerea on MB versus VB, and the plant defense mechanisms deployed to stop the fungus spreading. On the pathogen side, our genome-wide transcriptomic data revealed that B. cinerea genes upregulated during infection of MB are enriched in functional categories related to necrotrophy, such as degradation of the plant cell wall, proteolysis, membrane transport, reactive oxygen species (ROS) generation, and detoxification. Quantitative-polymerase chain reaction on a set of representative genes related to virulence and microscopic observations further demonstrated that the infection is also initiated on VB but is stopped at the penetration stage. On the plant side, genome-wide transcriptomic analysis and metabolic data revealed a defense pathway switch during berry ripening. In response to B. cinerea inoculation, VB activated a burst of ROS, the salicylate-dependent defense pathway, the synthesis of the resveratrol phytoalexin, and cell-wall strengthening. On the contrary, in infected MB, the jasmonate-dependent pathway was activated, which did not stop the fungal necrotrophic process.
The fungus Botrytis cinerea is the causal agent of the economically important gray mold disease that affects more than 200 ornamental and agriculturally important plant species. B. cinerea is a ...necrotrophic plant pathogen that secretes nonspecific phytotoxins, including the sesquiterpene botrydial and the polyketide botcinic acid. The region surrounding the previously characterized BcBOT1 gene has now been identified as the botrydial biosynthetic gene cluster. Five genes including BcBOT1 and BcBOT2 were shown by quantitative reverse transcription-PCR to be co-regulated through the calcineurin signaling pathway. Inactivation of the BcBOT2 gene, encoding a putative sesquiterpene cyclase, abolished botrydial biosynthesis, which could be restored by in trans complementation. Inactivation of BcBOT2 also resulted in overproduction of botcinic acid that was observed to be strain-dependent. Recombinant BcBOT2 protein converted farnesyl diphosphate to the parent sesquiterpene of the botrydial biosynthetic pathway, the tricyclic alcohol presilphiperfolan-8β-ol.
Botrytis cinerea, the grey mould fungus, secretes non-host-specific phytotoxins that kill the cells of many plant species. Phytotoxic assays performed about ten years ago, have highlighted the role ...in the infection mechanism of one of these secondary metabolites, the sesquiterpene botrydial. We recently showed that BcBOT1 to BcBOT5 genes, which are required for botrydial biosynthesis, are organised into a physical cluster. However, this cluster includes no gene encoding a transcription factor (TF) that might specifically coregulate the expression of BcBOT genes. To identify which TF(s) are implicated in the regulation of this cluster and thereby to decipher DNA-protein interactions in the phytopathogenic fungus B. cinerea, we developed a strategy based on the yeast one-hybrid (Y1H) method. In this study, a Y1H library was generated with the TFs predicted from complete genome sequencing. The screening of this library revealed an interaction between a promoter of the botrydial biosynthesis gene cluster and a new Cys2His(2) zinc finger TF, that we called BcYOH1. Inactivation of the BcYOH1 gene and expression analyses demonstrated the involvement of this IF in regulating expression of the botrydial biosynthesis gene cluster. Furthermore, whole-transcriptome analysis suggested that BcYOH1 might act as a global transcriptional regulator of phytotoxin and other secondary metabolism gene clusters, and of genes involved in carbohydrate metabolism, transport, virulence and detoxification mechanisms. (C) 2013 Elsevier Inc. All rights reserved.
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