Silvina Gonzalez-Rizzo

University of the French Antilles | Reunion · Department of Biology

Cells of most bacterial species are around 2 micrometers in length, with some of the largest specimens reaching 750 micrometers. Using fluorescence, x-ray, and electron microscopy in conjunction with genome sequencing, we characterized Candidatus ( Ca. ) Thiomargarita magnifica, a bacterium that has an average cell length greater than 9000 micromet...

Cells of most bacterial species are around 2 µm in length, with some of the largest specimens reaching 750 µm. Using fluorescence, x-ray, and electron microscopy in conjunction with genome sequencing, we characterized Ca. Thiomargarita magnifica, a bacterium with an average cell length greater than 9,000 µm that is visible to the naked eye. We foun...

Sequencing and other biological data are now more frequently available and at a lower price. Mutual tools and strategies are needed to analyze the huge amount of heterogeneous data generated by several research teams and devices. Bioinformatics represents a growing field in the scientific community globally. This multidisciplinary field provides a...

Current research on microbial fuel cell or microbial electrolysis cell dealt with finding new electroactive bacteria and understanding the mechanisms of electronic exchange. Complex consortia allowed to obtain better performances than pure cultures in part thanks to inter-species cooperation. However, the role of each bacterium in a complex biofilm...

The soil environmental conditions and symbiotic interactions are the major determinants of legume root architecture. Investigating cues that affect root developmental adaptations to the environment as well as understanding the mechanisms underlying the control of the root architecture are crucial to improve agronomical traits, notably in the legume...

Ehrlichia ruminantium is an obligatory intracellular bacterium that causes heartwater, a fatal disease in ruminants. Due to its intracellular nature, E. ruminantium requires a set of specific virulence factors, such as the type IV secretion system (T4SS), and outer membrane proteins (Map proteins) in order to avoid and subvert the host's immune res...

Nucleotide sequence of the predicted erxR promoter. The initiation codon of erxR is shown in capital letters at the end of the sequence. The sequence in red represents the nATWAT motif. The−35 and−10 boxes of the erxR promoter are capitalized. (B) The potential erxR Fur box is compared with the consensus E. coli Fur box. Conserved residues are show...

Oligonucleotide primers used to construct plasmids.

Oligonucleotide primers used for qPCR and qRT-PCR.

Strains and plasmids used in this work.

Since the discovery of thioautotrophic bacterial symbiosis in the giant tubeworm Riftia pachyptila, there has been great impetus to investigate such partnerships in other invertebrates. In this study, we present the occurrence of a sulphur-oxidizing symbiosis in a metazoan belonging to the phylum Cnidaria in which this event has never been describe...

Beggiatoaceae, giant sulphur-oxidizing bacteria, are well known to occur in cold and temperate waters, as well as hydrothermal vents, where they form dense mats on the floor. However, they have never been described in tropical marine mangroves. Here, we describe two new species of benthic Beggiatoaceae colonizing a marine mangrove adjacent to mangr...

In this multidisciplinary study, we combined morphological, physiological and phylogenetic approaches to identify three dominant water-bloom-forming cyanobacteria in a tropical marine mangrove in Guadeloupe (French West Indies). Phylogenetic analysis based on 16S rRNA gene sequences place these marine cyanobacteria in the genera Oscillatoria (Oscil...

Haplognathia ruberrima is a cosmopolitan gnathostomulid species found in sulfur bacterial mats in mangroves in Guadeloupe (French West Indies). Haplo-gnathia ruberrima presents a d 13 C value lower than all measured meiofaunal grazers and lower than the available measured food sources of this environment. This low d 13 C value can not be due to spe...

The soil environmental conditions and symbiotic interactions are the major determinants of legume root architecture. Investigating cues that affect root developmental adaptations to the environment as well as understanding the mechanisms underlying the control of the root architecture are crucial to improve agronomical traits, notably in the legume...

A family of plant kinases containing ankyrin-repeats, the Ankyrin-Protein Kinases (APKs), shows structural resemblance to mammalian Integrin-Linked Kinases (ILKs), key regulators of mammalian cell adhesion. MsAPK1 expression is induced by osmotic stress in roots of Medicago sativa (L.) plants. The Escherichia coli-purified MsAPK1 could only phospho...

The efficient acquisition of soil resources (nutrients and water) through the root system is crucial for crop productivity. In order to adapt root growth to the soil environment, plants can optimize their root architecture by initiating primordia and influencing growth of primary roots or lateral roots (LRs). Root architecture results from the inte...

Root growth and function are determined by the action of environmental stresses through specific genes that adapt root development to these restrictive conditions. We have defined in vitro conditions affecting the growth and recovery of Medicago truncatula roots after a salt stress. A dedicated macroarray containing 384 genes, based on a large-scal...

Medicago spp. are able to develop root nodules via symbiotic interaction with Sinorhizobium meliloti. Calcium-dependent protein kinases (CDPKs) are involved in various signalling pathways in plants, and we found that expression of MtCPK3, a CDPK isoform present in roots of the model legume Medicago truncatula, is regulated during the nodulation pro...

Legumes develop different types of lateral organs from their primary root, lateral roots and nodules, the latter depending on a symbiotic interaction with Sinorhizobium meliloti. Phytohormones have been shown to function in the control of these organogeneses. However, related signaling pathways have not been identified in legumes. We cloned and cha...