Study of Defense-related Gene Expression in Grapevine Leaves and Berries Infected with Botrytis cinerea

Defense responses of grapevine towards Botrytis cinerea were investigated. The expression of genes coding for proteins involved in defense were studied: (a) phenylalanine ammonia-lyase (PAL) and stilbene synthase (StSy), (b) an acidic chitinase (VCH3) and a basic chitinase (VCHIT1b), and (c) a polygalacturonase inhibitor protein (PGIP). Since no PGIP was known in grapevine, a complete cDNA sequence was first characterized by PCR and RACE-PCR amplifications. RNAs isolated from infected leaves and infected berries were analysed by semi-quantitative and real-time RT-PCRs. In infected leaves, the expression of PAL, StSy, PGIP and VCH3 genes occurred 6hours post inoculation (hpi). Increase of VCHIT1b gene expression was delayed (24hpi). Maximum levels of induction of these genes were observed at 48hpi, except for the VCH3 gene (24hpi). Activation of these defense responses was not sufficient to stop B. cinerea spread. In berries, no VCH3 gene expression was detected. Maximum levels of induction were observed in stage 3 (loss of berry colour and abundant production of conidia) for the PAL and PGIP genes, and in stage 4 (shrivelled berry) for the StSy and VCHIT1b genes.     

Description ofPauesia (Pauesia)anatolica (Hymenoptera: Braconidae, Aphidiinae) sp. nov., a parasitoid of the cedar aphidCinara cedri

The first parasitoid species reared from a population of the cedar aphid,Cinara cedri Mimeur, 1935 (Hemiptera: Aphididae), from the peninsula of Anatolia in Turkey is described.Pauesia anatolica (Hymenoptera: Braconidae, Aphidiinae) is closely related to some species of thelaricis group ofPauesia from which it differs in the number of antenomers, the propodeum and features of the female genitalia. Its potential use as a natural enemy in areas where the aphid has been introduced is discussed. http://www.phytoparasitica.org posting Aug. 28, 2005.     

Thermal weed control technologies for conservation agriculture—a review

Research and development activities on non-chemical weed control methods to date have mainly focused on mechanical and thermal applications. Selectivity in mechanical weed control is obtained using dynamically actuated harrows. Selectivity in thermal weed control is obtained through a certain heat tolerance of the crop. In conservation agriculture (CA), weed emergence is partially suppressed by constant soil cover with crops or cover crops. Large amounts of plant residues therefore remain on the soil, which make mechanical methods inefficient or difficult to implement. And thermal methods need to prevent not only crop damage but also fire from situationally dry plant residues. In this review, technologies that can potentially be used for in-crop weed control in CA are discussed. The technologies reviewed include spot-flaming, electric resistance heating, electromagnetic irradiation and steam/hot water application. Their evaluation focuses on efficiency and specificity (spatial precision). This review indicates that existing equipment does not fulfil the spatial precision required in CA and that further research and development is required on this topic. In particular, the authors suggest further research on the use of laser diodes, micro-flames and capacitive coupling of electric fields. It seems that the use of automated imaging systems for weed/crop differentiation is a prerequisite in CA to enable automatisation of weed control.     

A survey investigating the current practice of French health professionals regarding infection risk after monkey bites

International tourism is steadily increasing, with 15% of travellers reporting health problems when they come back. Animal bites represent 2% of consulting causes, of which 20% are due to monkey bites. The Monkey B virus (Macacine alphaherpesvirus 1) is an alphaherpesvirus (Herpesviridae, genus Simplexvirus) enzootic in macaques (Genus Macaca). Zoonotic infections with the Monkey B virus following exposure to macaques are exceptionally rare, but can cause fatal encephalomyelitis in humans. An observational survey was undertaken in 2018 to assess the practice of French health professionals regarding infection risk after monkey bites. French health professionals practicing in vaccination and rabies centres were specifically targeted for this study. Standardized questionnaires were sent by email to a sample of French health professionals. They were asked to participate on a voluntary and anonymous basis. The questionnaires requested epidemiological details and included multiple‐choice questions about the infection management of monkey bites. The response rate was 33.5%. The frequency of monkey bites in 2017 was variable with a minority of centres managing more than 6 per year (12%), 46% managing 1–5 monkey bites and 42% none. Most of the monkey bites were described as occurring in South Asia at tourist sites, on naked upper limbs, shortly after the travellers arrived at their destination. Tetanus status verification, rabies post‐exposure prophylaxis and antibiotic therapy were said to be prescribed in most cases. Knowledge about the Monkey B virus was reported as scarce for 38% of the participants. The number of monkey bites managed per year per centre varied greatly but practices regarding infectious risk after monkey bites were generally homogeneous. The risk of Monkey B virus transmission did not readily come to mind in the differential diagnosis of infection risk for many French health professionals.     

Improved resistance against Botrytis cinerea by grapevine-associated bacteria that induce a prime oxidative burst and phytoalexin production

Bacteria such as Pantoea agglomerans (Pa-AF2), Bacillus subtilis (Bs-271), Acinetobacter lwoffii (Al-113), and Pseudomonas fluorescens (Pf-CT2), originating from the vineyard, can induce defense responses and enhance resistance of grapevine against the fungal pathogen Botrytis cinerea. The perception of these bacteria by plant cells or tissues in relation to their activities remains unknown. In this study, we examined the relationships between the activity of each bacterium to induce or prime some defense responses, and its effectiveness to induce resistance in grapevine against B. cinerea. We showed that all selected bacteria are capable of inducing early oxidative burst and phytoalexin (trans-resveratrol and trans-ε-viniferin) production in grapevine cells and leaves. Pf-CT2 and Al-113 induced higher H(2)O(2) and trans-resveratrol accumulations, and were able to further prime plants for accelerated phytoalexin production after B. cinerea challenge. These two bacteria were also the most effective in inducing local and systemic resistance. A similar level of induced resistance was observed with live Pa-AF2 which also induced but not primed a greater accumulation of trans-resveratrol. However, Bs-271, which was less effective in inducing resistance, induced a lower trans-resveratrol synthesis, without priming activity. Treatment of grapevine cells with growing medium or crude extract of the bacteria quickly and strongly enhanced oxidative burst compared with the live bacteria. However, both treatments resulted in comparable amounts of phytoalexins and induced local and systemic resistance to B. cinerea as compared with those induced by living bacteria, with extracts from Pf-CT2 and Al-113 being the most effective. Together, these results indicate that induced resistance can be improved by treatment with bacteria or derived compounds which induced or primed plants for enhanced phytoalexin accumulation.     

Use of high spatial resolution satellite imagery to characterize landscapes at risk for bluetongue

The recent and rapid spread in the Mediterranean Basin of bluetongue, a viral disease of ruminants transmitted by some species of Culicoides (biting midges), highlights the necessity of determining the conditions of its emergence. This study uses high spatial resolution satellite imagery and methods from landscape ecology science to identify environmental parameters related to bluetongue occurrence in Corsica, a French Mediterranean island where the disease occurred for the first time in 2000. A set of environmental variables recorded in the neighborhood of 80 sheep farms were related to case occurrence through a logistic regression model computed within three subsequent buffer distances of 0.5, 1 and 2 km. The results reveal the role of landscape metrics, particularly those characterizing land-use units such as prairies and woodlands, as well as farm type, latitude and sunshine to explain the presence of bluetongue. Internal and external validation both indicate that the best results are obtained with the 1 km buffer size model (area under Receiver Operating Characteristic curve = 0.9 for internal validation and 0.81 for external validation). The results show that high spatial resolution remote sensing (i.e. 10 m pixels) and landscape ecology approaches contribute to improving the understanding of bluetongue epidemiology.     

Ocular findings in two colonies of gray mouse lemurs (Microcebus murinus)

OBJECTIVE: To determine the incidence and describe the characteristics of cataracts and other ocular lesions found in two colonies of gray mouse lemurs (Microcebus murinus). ANIMALS STUDIED: A total number of 218 mouse lemurs (age range: 4 months-11 years) were included in this study. All individuals were property of the Muséum National d'Histoire Naturelle (France), and were housed either in Paris (colony #1: 75 animals examined), or in Brunoy (colony #2: 143 animals). METHODS: Ocular examinations were performed on all animals before and after pupil dilation, and included slit-lamp biomicroscopy and indirect ophthalmoscopy. In both colonies, a limited number of individuals were re-examined between several months and 2 years following the initial eye examinations. The eyes of five mouse lemurs with incipient or immature cataracts that died during this period were collected, and processed for routine histopathologic examination. RESULTS: A high incidence of cataracts was observed in both colonies (48% in colony #1; 21% in colony #2). Cataracts were predominantly bilateral, started in the anterior and/or posterior subcapsular area, and appeared to be slowly progressive. The earliest age at which lens opacities were observed was 3.5 years, and more than 50% of mouse lemurs over 7 years of age were diagnosed with cataracts. Complete cataracts led to blindness and were occasionally associated with other ocular lesions. CONCLUSION: We report a high incidence of acquired, slowly progressive, bilateral cataracts in two colonies of mouse lemurs (Microcebus murinus). Further studies need to be conducted to determine the cause of this disease in this species.     

Complex Toxin Profile of French Mediterranean Ostreopsis cf. ovata Strains,Seafood Accumulation and Ovatoxins Prepurification

Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins have hemolytic properties. An average of 223 μg·kg⁻¹ of palytoxin equivalent of whole flesh was found, thus exceeding the threshold of 30 μg·kg⁻¹ in shellfish recommended by the European Food Safety Authority (EFSA). Ostreopsis cells showed the same toxin profile both in situ and in laboratory culture, with ovatoxin-a (OVTX-a) being the most abundant analogue (~50%), followed by OVTX-b (~15%), p-PLTX (12%), OVTX-d (8%), OVTX-c (5%) and OVTX-e (4%). Ostreopsis cf. ovata produced up to 2 g of biomass per L of culture, with a maximum concentration of 300 pg PLTX equivalent cell⁻¹. Thus, an approximate amount of 10 mg of PLTX-group toxins may be produced with 10 L of this strain. Toxin extracts obtained from collected biomass were purified using different techniques such as liquid-liquid partition or size exclusion. Among these methods, open-column chromatography with Sephadex LH20 phase yielded the best results with a cleanup efficiency of 93% and recovery of about 85%, representing an increase of toxin percentage by 13 fold. Hence, this purification step should be incorporated into future isolation exercises.