Role of Methyl Salicylate on Oviposition Deterrence in Arabidopsis thaliana

Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae

Comparaison d'un entraînement de renforcement classique à un entraînement complexe sur Dynamic Leg Press pour une préparation optimale d'une saison de ski: étude pilote

Il existe diverses directives concernant des entraînements simples pour améliorer la force maximale ou la puissance. Mais de plus en plus d’appareils de tonification se construisent pour entraîner plusieurs facultés à la fois. Le premier objectif de cette étude est d’évaluer si un entraînement complexe multimodal s’avère plus efficace qu’un entraînement classique au niveau de la force maximale, de la puissance, de l’équilibre ainsi que de la précision du geste. Deuxièmement, nous aimerions évaluer la faisabilité de cette étude

Insect eggs induce a systemic acquired résistance in Arabidopsis thaliana

Although they constitute an inert stage of the insect's life, eggs trigger plant defenses that lead to egg mortality or attraction of egg parasitoids. It was recently found that salicylic acid (SA) accumulâtes in response to oviposition by the Large White butterfly Pieris brassicae, both in local and systemic Arabidopsis leaves. In addition, eggs induced a response that is similar to the récognition of pathogen-associated molecular patterns (PAMPs), which are involved in PAMP-triggered immunity (PTI). In this thesis, I demonstrate that natural oviposition by P. brassicae or treatment with egg extract inhibit growth of différent Pseudomonas syringae strains in Arabidopsis thaliana through the activation of a systemic acquired résistance (SAR). This egg-induced SAR involves the metabolic SAR signal pipecolic acid, depends on ALD1 and FMOl, and is accompanied by a priming of defense genes upon secondary infection. Moreover, I found that ICSl-dependent SA accumulation was not required for SAR establishment but that it depends on MPK3 and MPK6 sustained activation. Furthermore, I found that components of the indole metabolism are needed to inhibit pathogen growth in systemic leaves. Additionally, the résistant state is not only efficient against bacteria but has a broad-range spectrum, rendering the plant more résistant against différent pathogens such as the necrotrophic fungus Botrytis cinerea or the oomycete Hyaloperonospora arabidopsidis. Finally, although P. brassicae larvae showed a reduced performance when feeding on P. syringae-infected plants, this effect was less pronounced when infected plants had been previously subjected to oviposition. This unique phenomenon might illustrate a strategy by insect eggs to manipulate plant defenses and prevent the detrimental effect of pathogens on feeding. Larvae. Altogether these findings may open the way for a potential use of egg-extract as priming agent in agronomy

Summary of the domains assessed with the INTERMED.

<p>(adapted from De Jonge P et al 2003 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094268#pone.0094268-deJonge2" target="_blank">[51]</a>, a full description of domains assessed in the INTERMED is available at: <a href="http://www.intermedfoundation.org/" target="_blank">http://www.intermedfoundation.org/</a>).</p

Non-return to work: Odds ratios for the univariable, multivariable and the reduced model after random forest selection process.

<p>Odds Ratios of the different models in the development sample, with corresponding 95% confidence intervals (CI).</p

Flow chart of patients through the study.

<p>Flow chart of patients through the study.</p

Summary of the domains assessed with the INTERMED.

<p>(adapted from De Jonge P et al 2003 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094268#pone.0094268-deJonge2" target="_blank">[51]</a>, a full description of domains assessed in the INTERMED is available at: <a href="http://www.intermedfoundation.org/" target="_blank">http://www.intermedfoundation.org/</a>).</p

Characteristics of the development and validation study population overall and by return to work status.

<p>For the development sample only patients included with complete data on all variables and for the validation sample only patients with complete data on the variables from the final model are shown. AIS: Abbreviated Injury Scale.</p

Proportions of true-positives (TP), false-positives (FP), true-negatives (TN) and false-negatives (FN) given by the Reduced Model in the temporal validation sample, according to threshold of 0.5 (sample with 100 patients).

<p>Proportions of true-positives (TP), false-positives (FP), true-negatives (TN) and false-negatives (FN) given by the Reduced Model in the temporal validation sample, according to threshold of 0.5 (sample with 100 patients).</p