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Université de Fribourg

Dissecting the ß-aminobutyric acid–induced priming phenomenon in Arabidopsis

Ton, Jurriaan ; Jakab, Gabor ; Toquin, Valérie ; Flors, Victor ; Iavicoli, Annalisa ; Maeder, Muriel N. ; Métraux, Jean-Pierre ; Mauch-Mani, Brigitte

In: The Plant Cell, 2005, vol. 17, p. 987-999

Plants treated with the nonprotein amino acid ß-aminobutyric acid (BABA) develop an enhanced capacity to resist biotic and abiotic stresses. This BABA-induced resistance (BABA-IR) is associated with an augmented capacity to express basal defense responses, a phenomenon known as priming. Based on the observation that high amounts of BABA induce sterility in Arabidopsis thaliana, a mutagenesis...

Université de Fribourg

Developmental origin of wiring specificity in the olfactory system of Drosophila

Jefferis, Gregory S. X. E. ; Vyas, Raj M. ; Berdnik, Daniela ; Ramaekers, Ariane ; Stocker, Reinhard F. ; Tanaka, Nobuaki K. ; Ito, Kei ; Luo, Liqun

In: Development, 2004, vol. 131, p. 117-130

In both insects and mammals, olfactory receptor neurons (ORNs) expressing specific olfactory receptors converge their axons onto specific glomeruli, creating a spatial map in the brain. We have previously shown that second order projection neurons (PNs) in Drosophila are prespecified by lineage and birth order to send their dendrites to one of ~50 glomeruli in the antennal lobe. How can a given...

Université de Fribourg

Sulphur deficiency causes a reduction in antimicrobial potential and leads to increased disease susceptibility of oilseed rape

Dubuis, Pierre-Henri ; Marazzi, Cristina ; Städler, Erich ; Mauch, Felix

In: Journal of Phytopathology, 2005, vol. 153, p. 27-36

The reduction of atmospheric sulphur dioxide pollution is causing increasing problems of sulphur deficiency in sulphur-demanding crop plants in northern Europe. Elemental sulphur and many sulphur containing compounds such as cysteine-rich antifungal proteins, glucosinolates (GSL) and phytoalexins play important roles in plant disease resistance. The aim of this work was to analyse the effect of...

Université de Fribourg

Gene-specific Involvement of ß-oxidation in wound-activated responses in Arabidopsis

Castillo, M. Cruz ; Martínez, Cristina ; Buchala, Antony ; Métraux, Jean-Pierre ; León, José

In: Plant Physiology, 2004, vol. 135, p. 95-104

The coordinated induced expression of ß-oxidation genes is essential to provide the energy supply for germination and postgerminative development. However, very little is known about other functions of ß-oxidation in nonreserve organs. We have identified a gene-specific pattern of induced ß-oxidation gene expression in wounded leaves of Arabidopsis. Mechanical damage triggered the local and...

Université de Fribourg

Crosstalk and differential response to abiotic and biotic stressors reflected at the transcriptional level of effector genes from secondary metabolism

Glombitza, Sabine ; Dubuis, Pierre-henri ; Thulke, Oliver ; Welzl, Gerhard ; Bovet, Lucien ; Götz, Michael ; Affenzeller, Matthias ; Geist, Birgit ; Hehn, Alain ; Asnaghi, Carole ; Ernst, Dieter ; Seidlitz, Harald ; Gundlach, Heidrun ; Mayer, Klaus ; Martinoia, Enrico ; Werck-reichhart, Daniele ; Mauch, Felix ; Schäffner, Anton

In: Plant Molecular Biology, 2005, vol. 54, p. 817-835

Plant secondary metabolism significantly contributes to defensive measures against adverse abiotic and biotic cues. To investigate stress-induced, transcriptional alterations of underlying effector gene families, which encode enzymes acting consecutively in secondary metabolism and defense reactions, a DNA array (MetArray) harboring gene-specific probes was established. It comprised complete sets...

Université de Fribourg

Toward a digital database of plant cell signalling networks: advantages, limitations and predictive aspects of the digital model

Treviño Santa Cruz, Marcela Beatriz ; Genoud, Dominique ; Métraux, Jean-Pierre ; Genoud, Thierry

In: Phytochemistry, 2005, vol. 66, p. 267-277

The process of signal integration, which contributes to the regulation of multiple cellular activities, can be described in a digital language by a set of connected digital operations. In this article we delineate the basic concepts of cell signalling in the context of a logical description of information processing. Newly described instances of signal integration in plants are given as examples....

Université de Fribourg

A new structural element containing glycine-rich proteins and rhamnogalacturonan I in the protoxylem of seed plants

Ryser, Ulrich ; Schorderet, Martine ; Guyot, Romain ; Keller, Beat

In: Journal of Cell Science, 2004, vol. 117, p. 1179-1190

The water pipes of elongating plant organs are the result of programmed cell death and are formed by the walls of dead and empty protoxylem elements. These protoxylem elements are passively elongated many times by the surrounding tissue before they are replaced and collapse. Well-known adaptations for this unique task include the characteristic secondary wall thickenings, forming rings and...

Université de Fribourg

The effect of learning on experimental evolution of resource preference in Drosophila melanogaster

Kawecki, Tadeusz J. ; Mery, Frederic

In: Evolution, 2004, vol. 58, no. 4, p. 757-767

Learning is thought to be adaptive in variable environments, whereas constant, predictable environments are supposed to favor unconditional, genetically fixed responses. A dichotomous view of behavior as either learned or innate ignores a potential evolutionary interaction between the learned and innate components of a behavioral response. We addressed this interaction in the context of...

Université de Fribourg

Nuclear receptors as vehicles for gene transfer

Ceppi, Maurizio ; Rusconi, Sandro (Dir.)

Thèse de doctorat : Université de Fribourg : 2000 ; Nr. 1328.

Human gene therapy can be defined as the directed transfer of exogenous genes or other nucleotide sequences into somatic cells, for the purpose of preventing, correcting or healing various diseases. This novel approach to the therapy of human disorders is based on the realization that many previous medical treatments have usually been directed at the consequences of causative defects or at...

Université de Fribourg

Experimental Evolutionary Biology of Learning in “drosophila melanogaster”

Mery, Frederic ; Kawecki, Tadeusz (Dir.)

Thèse de doctorat : Université de Fribourg : 2003 ; 1403.

La plupart des animaux, invertébrés inclus, ont la capacité de modifier leur comportement à la suite d'expériences, ils sont capables d'apprendre. Leur capacité d'apprentissage est elle-même un produit de l'évolution et le degré de modification d'un comportement par l'apprentissage varie selon les espèces et selon le comportement considéré. Pour un biologiste de l'évolution ceci...