Improved control of Septoria tritici blotch in durum wheat using cultivar mixtures

Mixtures of cultivars with contrasting levels of disease resistance are capable of suppressing infectious diseases in wheat, as demonstrated in numerous field experiments. Most studies focused on airborne pathogens in bread wheat, while splash-dispersed pathogens have received less attention, and no studies have been conducted in durum wheat. We conducted a two-year field experiment in Tunisia, a major durum wheat producer in the Mediterranean region, to evaluate the performance of cultivar mixtures in controlling the polycyclic, splash-dispersed disease Septoria tritici blotch (STB) in durum wheat. To measure STB severity, we used a novel, high-throughput method based on digital analysis of images captured from 3074 infected leaves collected from 42 and 40 experimental plots on the first and the second year, respectively. This method allowed us to quantify pathogen reproduction on wheat leaves and to acquire a large dataset that exceeds previous studies with respect to accuracy and statistical power. Our analyses show that introducing only 25% of a disease-resistant cultivar into a pure stand of a susceptible cultivar provides a substantial reduction of almost 50% in disease severity. However, adding a second resistant cultivar to the mixture did not further improve disease control, contrary to predictions of epidemiological theory. Susceptible cultivars can be agronomically superior to resistant cultivars or be better accepted by growers for other reasons. Hence, if mixtures with only a moderate proportion of the resistant cultivar provide similar degree of disease control as resistant pure stands, as our analysis indicates, such mixtures are more likely to be accepted by growers

Use of 3-D Digital Image Correlation to describe the mechanical behavior of Wood Plastic Composites (WPC)

National audienceno abstrac

Membrane asymmetry imposes directionality on lipid droplet emergence from the ER

During energy bursts, neutral lipids fabricated within the ER bilayer demix to form lipid droplets (LDs). LDs bud off mainly in the cytosol where they regulate metabolism and multiple biological processes. They indeed become accessible to most enzymes and can interact with other organelles. How such directional emergence is achieved remains elusive. Here, we found that this directionality is controlled by an asymmetry in monolayer surface coverage. Model LDs emerge on the membrane leaflet of higher coverage, which is improved by the insertion of proteins and phospholipids. In cells, continuous LD emergence on the cytosol would require a constant refill of phospholipids to the ER cytosolic leaflet. Consistent with this model, cells deficient in phospholipids present an increased number of LDs exposed to the ER lumen and compensate by remodeling ER shape. Our results reveal an active cooperation between phospholipids and proteins to extract LDs from ER

Dual binding motifs underpin the hierarchical association of perilipins1-3 with lipid droplets.

Lipid droplets (LDs) in all eukaryotic cells are coated with at least one of the perilipin family of proteins. They all regulate key intracellular lipases but do so to significantly different extents. Where more than one perilipin is expressed in a cell, they associate with LDs in a hierarchical manner. In vivo, this means that lipid flux control in a particular cell or tissue type is heavily influenced by the specific perilipins present on its LDs. Despite their early discovery, exactly how perilipins target LDs and why they displace each other in a ‘hierarchical’ manner remains unclear. They all share an amino-terminal 11-mer repeat amphipathic region suggested to be involved in LD targeting. Here, we show that in vivo this domain functions as a primary highly reversible LD targeting motif in perilipins1-3 and, in vitro, we document reversible and competitive binding between a wildtype purified perilipin1 11-mer repeat peptide and a mutant with reduced binding affinity to both ‘naked’ and phospholipid coated oil-water interfaces. We also present data suggesting that a second carboxy-terminal 4-helix bundle domain stabilizes LD binding in perilipin1 more effectively than in perilipin2, whereas in perilipin3 it weakens binding. These findings suggest that dual amphipathic helical regions mediat

Dual binding motifs underpin the hierarchical association of perilipins1-3 with lipid droplets.

Lipid droplets (LDs) in all eukaryotic cells are coated with at least one of the perilipin (Plin) family of proteins. They all regulate key intracellular lipases but do so to significantly different extents. Where more than one Plin is expressed in a cell, they associate with LDs in a hierarchical manner. In vivo, this means that lipid flux control in a particular cell or tissue type is heavily influenced by the specific Plins present on its LDs. Despite their early discovery, exactly how Plins target LDs and why they displace each other in a "hierarchical" manner remains unclear. They all share an amino-terminal 11-mer repeat (11mr) amphipathic region suggested to be involved in LD targeting. Here, we show that, in vivo, this domain functions as a primary highly reversible LD targeting motif in Plin1-3, and, in vitro, we document reversible and competitive binding between a wild-type purified Plin1 11mr peptide and a mutant with reduced binding affinity to both "naked" and phospholipid-coated oil-water interfaces. We also present data suggesting that a second carboxy-terminal 4-helix bundle domain stabilizes LD binding in Plin1 more effectively than in Plin2, whereas it weakens binding in Plin3. These findings suggest that dual amphipathic helical regions mediate LD targeting and underpin the hierarchical binding of Plin1-3 to LDs

Papulose bowenóide: um aspecto clínico da infecção pelo HPV Bowenoid papulosis: a clinical feature of the HPV infection

Papulose bowenóide é uma doença que acomete a pele da região anogenital e que se caracteriza pelas múltiplas pequenas pápulas planas ou aveludadas e de coloração que varia do róseo ao castanho-escuro. É provocada pelo HPV e a transmissão sexual é a forma mais freqüente de contaminação. As queixas mais comuns são prurido e dor. O aspecto é característico e o exame histopatológico confirma o diagnóstico. Junto com a doença de Bowen e a eritroplasia de Queyrat, é considerada como carcinoma in situ, ou neoplasia intra-epitelial de alto grau (NIAA), a lesão precursora do carcinoma espinocelular (CEC) anal. Sem tratamento, a maioria das lesões permanece benigna e estável. Várias modalidades terapêuticas estão disponíveis, incluindo as medicações tópicas para citodestruição e as técnicas ablativas. Os esquemas tópicos são efetivos. Cabe ao profissional médico escolher a terapia adequada, tendo em mente que a doença é benigna e raramente evolui para carcinoma. Como as recidivas são freqüentes e ainda persistem dúvidas quanto ao potencial de malignização, os doentes devem ser examinados periodicamente para diagnosticar as lesões iniciais.<br>Bowenoid papulosis is an anogenital skin disease characterized by multiple little papules, flat or velvet, which color varies from pink to dark brown. It is provoked by HPV and its transmission is sexual. Most common symptoms are anal pain and itching. Its appearance is characteristic and hystopathological examination confirms diagnosis. Together with Bowen´s disease and Queyrat erythroplasia, is considered as an in situ carcinoma, or high grade intra-epithelial neoplasia (HAIN), a precursor of the squamous-cell carcinoma. Most of lesions remain benign and stable without treatment. There are several kinds of treatment including topical drugs for cytodestruction and ablative techniques. Topic schemes are effectives. The consultant doctor may choose the most adequate therapy, keeping in mind this disease is benign and rarely evolutes to invasive carcinoma. As recurrences are frequent and remain doubts about malign potential, patients must be examined periodically to diagnose initial lesions