0000000000918159
AUTHOR
Taline Elmayan
showing 12 related works from this author
Arabidopsis SGS2 and SGS3 genes are required for posttranscriptional gene silencing and natural virus resistance.
2000
AbstractPosttranscriptional gene silencing (PTGS) in plants results from the degradation of mRNAs and shows phenomenological similarities with quelling in fungi and RNAi in animals. Here, we report the isolation of sgs2 and sgs3 Arabidopsis mutants impaired in PTGS. We establish a mechanistic link between PTGS, quelling, and RNAi since the Arabidopsis SGS2 protein is similar to an RNA-dependent RNA polymerase like N. crassa QDE-1, controlling quelling, and C. elegans EGO-1, controlling RNAi. In contrast, SGS3 shows no significant similarity with any known or putative protein, thus defining a specific step of PTGS in plants. Both sgs2 and sgs3 mutants show enhanced susceptibility to virus, d…
NADPH Oxidase-Mediated Reactive Oxygen Species Production: Subcellular Localization and Reassessment of Its Role in Plant Defense
2009
International audience; Chemiluminescence detection of reactive oxygen species (ROS) triggered in tobacco BY-2 cells by the fungal elicitor cryptogein was previously demonstrated to be abolished in cells transformed with an antisense construct of the plasma membrane NADPH oxidase, NtrbohD. Here, using electron microscopy, it has been confirmed that the first hydrogen peroxide production occurring a few minutes after challenge of tobacco cells with cryptogein is plasma membrane located and NtrbohD mediated. Furthermore, the presence of NtrbohD in detergent-resistant membrane fractions could be associated with the presence of NtrbohD-mediated hydrogen peroxide patches along the plasma membran…
Regulation of plant NADPH oxidase.
2007
Addendum to: Regulation of Reactive Oxygen Species Production by a 14-3-3 Protein in Elicited Tobacco Cells. T. Elmayan, J. Fromentin, C. Riondet, G. Alcaraz, J. Blein and F. Simon-Plas. Plant Cell Environ 2007; 30:722–32; International audience; The production of Reactive Oxygen Species (ROS) is one of the key events occurring during the response of plants to environmental changes, and contributing to establish adaptive signaling pathways. A plasma membrane bound NADPH oxidase enzyme has been evidenced as the ROS producing system in various plant‑microorganisms interactions. We very recently reported, that a protein of the 14‑3‑3 family was able to interact directly with the C‑terminus par…
The fungal elicitor cryptogein induces cell wall modifications on tobacco cell suspension
2000
Upon addition of the fungal elicitor cryptogein, suspension cells of tobacco (Nicotiana tabacum cv. Xanthi) aggregated in clusters. Cytochemical experiments indicated that elicited cells displayed fibrillar expansions of pectin along the primary cell wall. Immunocytochemical detection of pectin epitopes indicated that the fibrillar material surrounding the treated cells was mostly composed of low methylated galacturonan sequences, but the use of the cationic probe did not reveal the presence of negatively charged carboxyl groups: the presence of important amounts of calcium ions in these pectic fibrillar expansions accounts for these observations. These data indicate that tobacco cells trea…
The plasma membrane oxidase NtrbohD is responsible for AOS production in elicited tobacco cells
2002
Summary A cDNA encoding a protein, NtrbohD, located on the plasma membrane and homologue to the flavocytochrome of the neutrophil NADPH oxidase, was cloned in tobacco. The corresponding mRNA was accumulated when tobacco leaves and cells were treated with the fungal elicitor cryptogein. After elicitation with cryptogein, tobacco cells transformed with antisense constructs of NtrbohD showed the same extracellular alkalinization as the control, but no longer produced active oxygen species (AOS). This work represents the first demonstration of the function of a homologue of gp91–phox in AOS production in elicited tobacco cells.
Rac regulation of NtrbohD, the oxidase responsible for the oxidative burst in elicited tobacco cell
2003
Five cDNAs encoding Rac protein homologues to the Rho-related proteins from plants (Rop) were isolated in tobacco, and the function of one of them, Ntrac5, was studied. The Ntrac5 mRNA is repressed when tobacco leaves and cells are treated with the fungal elicitor cryptogein. Tobacco cells were transformed with sense constructs of Ntrac5 or Ntrac5V15, encoding the native GTP/GDP-bound form of this Rac protein homologue or the constitutively active mutant in its GTP-bound form, respectively. Immunological studies indicate that the corresponding protein is continuously located on the plasma membrane (PM). Both types of transformed cells show the same extra-cellular alkalinization as the contr…
Regulation of reactive oxygen species production by a 14-3-3 protein in elicited tobacco cells.
2007
International audience; The regulation of the system responsible for the production of reactive oxygen species (ROS) during plant–microorganism interaction is still largely unknown. The protein NtrbohD has been recently demonstrated as the plasma membrane oxidase responsible for ROS production in elicited tobacco cells. Here, its C-terminus part was used as a bait in a two-hybrid screen in order to identify putative regulators of this system. This led to the isolation of a cDNA coding for a member of the 14-3-3 protein family. The corresponding transcript was induced after infiltration of tobacco leaves with the fungal elicitor cryptogein. Tobacco cells transformed with an antisense constru…
Cadmium in transgenic tobacco plants expressing a mammalian metallothionein gene
1997
International audience
Cloning of Rac and Rho-GDI from tobacco using an heterologous two-hybrid screen.
2000
International audience; To examine whether molecular similarities exist between the animal and plant Rho GTPase signaling pathways, we have developed a heterologous two-hybrid screening method. By this technique, we have cloned a cDNA encoding a tobacco Rac-like protein able to interact with a mammalian Rho-GDI. In a second screen this tobacco Rac was used as a bait and a tobacco homologue of Rho-GDI was identified. These results show that some components of the animal and plant Rac signaling pathways are similar enough to allow their interaction in an heterologous approach. Moreover these data suggest a similar regulation of Rho GTPases in animals and plants.
Origin of AOS production in tobacco cells elicited by cryptogein
2000
National audience
Rac regulation of NtrbohD, the oxidase responsible for the oxidative burst in elicited tobacco cell
2004
International audience
Requirement of sense transcription for homology-dependent virus resistance and trans-inactivation
1997
International audience