A fungal elicitor enhances the resistance of tomato fruit to Fusarium oxysporum infection by activating the phenylpropanoid metabolic pathway

Fungi infection in fruits is an important factor in postharvest losses. The effect of a treatment with a fungal elicitor on the response of tomato fruit to Fusarium oxysporum infection and changes in the phenylpropanoid metabolic pathway was studied. Fungal elicitor retarded for 3 days the development of the Fusarium rot development in tomato, at concentration of 2 g?l ^?1 (B2-F treatment). This treatment also induced a 3.11- and 6.03-fold increase of caffeic and chlorogenic acids, respectively, as compared with the control. Furthermore, the flavonoids naringenin-7-O-glucoside, rutin and kaempferol-3-O-glucoside, showed a greater abundance in tomato under the B2-F treatment after 6 days at 20°C. It is concluded that the fungal elicitor reduced the development of Fusarium rot by inducing the biosynthesis of metabolites from the phenylpropanoid metabolic pathway which forms part of the defense response in tomato fruit.     

The power of hyphenated chromatography/time-of-flight mass spectrometry in public health laboratories

Laboratories devoted to the public health field have to face the analysis of a large number of organic contaminants/residues in many different types of samples. Analytical techniques applied in this field are normally focused on quantification of a limited number of analytes. At present, most of these techniques are based on gas chromatography (GC) or liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS). Using these techniques only analyte-specific information is acquired, and many other compounds that might be present in the samples would be ignored. In this paper, we explore the potential of time-of-flight (TOF) MS hyphenated to GC or LC to provide additional information, highly useful in this field. Thus, all positives reported by standard reference targeted LC-MS/MS methods were unequivocally confirmed by LC-QTOF MS. Only 61% of positives reported by targeted GC-MS/MS could be confirmed by GC-TOF MS, which was due to its lower sensitivity as nonconfirmations corresponded to analytes that were present at very low concentrations. In addition, the use of TOF MS allowed searching for additional compounds in large-scope screening methodologies. In this way, different contaminants/residues not included in either LC or GC tandem MS analyses were detected. This was the case of the insecticide thiacloprid, the plant growth regulator paclobutrazol, the fungicide prochloraz, or the UV filter benzophenone, among others. Finally, elucidation of unknowns was another of the possibilities offered by TOF MS thanks to the accurate-mass full-acquisition data available when using this technique.     

Effect of some pesticides on plant growth,root nodulation and chlorophyll content of chickpea

Different concentrations, viz. 5, 10 and 25 ppm of aldicarb, carbofuran, phorate fensulfothion and fenamiphos were observed for their pesticidal effects on chickpea plant in terms of various plant growth parameters such as plant length as well as weight, pod numbers, root-nodulations and chlorophyl content. Significant improvement in plant growth was noted in lower concentrations such as 5 and 10 ppm of different pesticides but 5 ppm concentration proved highly effective and non-phytotoxic. The phytotoxic effect was noted in those plants treated with 25 ppm concentration of all the pesticides. Carbofuran was found to be most effective for improvement of over all plant growth and fensulfothion the least.     

4-Acetoxydolastane diterpene from the Brazilian brown alga Canistrocarpus cervicornis as antileishmanial agent

Natural marine products have shown an interesting array of diverse and novel chemical structures with potent biological activities. Our study reports the antiproliferative assays of crude extracts, fraction and pure compound (4R,9S,14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1) obtained from brown alga Canistrocarpus cervicornis showing the antileishmanial activity. We showed that 1 had a dose-dependent activity during 72 h of treatment, exhibiting IC(50) of 2.0 μg/mL, 12.0 μg/mL, and 4.0 μg/mL for promastigote, axenic amastigote and intracellular amastigote forms of Leishmania amazonensis, respectively. A cytotoxicity assay showed that the action of the isolated compound 1 was 93.0 times less toxic to the macrophage than to the protozoan. Additionally, compound 1 induced ultrastructural changes, including extensive mitochondrial damage; decrease in Rh123 fluorescence, suggesting interference with the mitochondrial membrane potential; and lipid peroxidation in parasite cells. The use of 1 from C. cervicornis against L. amazonensis parasites might be of great interest as a future alternative to the development of new antileishmanial drugs.     

Paratuberculosis in European wild rabbits from the Iberian Peninsula

Of the non-ruminant wildlife species known to harbor Mycobacterium avium paratuberculosis (MAP), the rabbit (Oryctolagus cuniculus) is thought to pose the greatest risk of transmission to cattle. We analyzed 80 hunter-harvested wild rabbits from a core study area in southern Spain, and sera from 157 wild rabbits sampled opportunistically on seven additional sites. Gross lesions compatible with paratuberculosis were observed in two of 80 necropsied rabbits. Histopathology revealed focal to diffuse multibacillary MAP-compatible lesions in 8 of 10 rabbits examined. Presence of MAP was confirmed in one rabbit with gross lesions by positive amplification curves for both IS900 and ISMAP02. However, no isolate was obtained from 47 samples by culture. We adapted an indirect ELISA for the detection of MAP antibodies. At the established cut-off of 0.5, 6 of 237 wild rabbit sera (2.5%) yielded a positive ELISA result. Antibodies were detected in rabbits from 3 of 8 sampling sites. Considering the increasing relevance of MAP infection for animal health, these results open a challenging field for future research.     

Peanut priming induced by biocontrol agents

Selected strains of rhizobacteria induce systemic resistance in plant (ISR), enhancing the capacity to mobilize infection-induced cellular defense responses (priming). Bacillus sp. CHEP5 and Pseudomonas sp BREN6 strains reduced root and stem wilt disease severity caused by Sclerotium rolfsii in Arachis hypogaea L. Strains inoculation increased the activity of phenylalanine ammonia-lyase and peroxidase, after pathogen-challenge, indicating priming. CHEP5 primes plants to produce more ethylene upon stimulation with ACC. A. hypogaea L is an ISR-positive plant and BREN6 and CHEP5 strains enhance the plant’s defense capacity by priming for potentiated activity of defense proteins and ACC-converting capacity.     

Truncating neurotrypsin mutation in autosomal recessive nonsyndromic mental retardation

A 4-base pair deletion in the neuronal serine protease neurotrypsin gene was associated with autosomal recessive nonsyndromic mental retardation (MR). In situ hybridization experiments on human fetal brains showed that neurotrypsin was highly expressed in brain structures involved in learning and memory. Immuno-electron microscopy on adult human brain sections revealed that neurotrypsin is located in presynaptic nerve endings, particularly over the presynaptic membrane lining the synaptic cleft. These findings suggest that neurotrypsin-mediated proteolysis is required for normal synaptic function and suggest potential insights into the pathophysiological bases of mental retardation.