Claire Parent

University of Franche-Comté | UFC · UMR 6249 Laboratoire Chrono-Environnement

Aquaporins (AQPs) belong to the Major Intrinsic Protein family that conducts water and other small solutes across biological membranes. This study aimed to identify and characterize AQP genes in the primary root axis of two oak species, Quercus petraea and Quercus robur. Nine putative AQP genes were cloned, and their expression was profiled in diff...

Climate change is projected to have a significant ecological impact on natural ecosystems, most notably through direct and indirect modifications of local precipitation regimes. In addition, anthropic activities such as the removal of vegetation, soil proofing due to building, the absence of storm drains and crop over-irrigation will all increase t...

Soil flooding is an environmental constraint that is increasingly important for forest ecosystems, affecting tree growth and regeneration. As a result, selection pressure will alter forest diversity and distribution by favouring tree species tolerant of soil oxygen deprivation. Sessile and pedunculate oaks are the most abundant oak species and they...

The cellular and molecular adaptations of non-model woody species to environmental changes are still poorly understood. We have cloned and characterised a novel non-symbiotic hemoglobin from oak roots (QpHb1) which exhibits a specific cellular distribution in the root. The QpHb1 gene is strongly expressed in the protoderm and the protoxylem cells i...

This study presents the isolation and characterization of a novel nonsymbiotic Hb gene from sessile oak (Quercus petraea) seedlings, herein designated QpHb1. The cellular and tissue expression of QpHb1 was analysed by Northern blotting and in situ hybridization. The encoded protein was predicted to consist of 161 amino acid residues, and shares 71...

Plant plastids generate signals, including some derived from lipids, that need to be mobilized to effect signaling. We used informatics to discover potential plastid membrane proteins involved in microbial responses in Arabidopsis (Arabidopsis thaliana). Among these are proteins co-regulated with the systemic immunity component AZELAIC ACID INDUCED...

In this study, a quantitative PCR (qPCR) method was applied to amplify ancient DNA (aDNA) of different methane-oxidizing bacteria (MOB) types in lake sediments and to reconstruct microbial community dynamics over the last 1200 years. We also used reconstructions of in-lake nutrients concentrations, air temperature fluctuations, and sedimentary orga...

Nitric oxide (NO) is a gaseous free radical recognized as a ubiquitous signal transducer that contributes to various biological processes in animals. It exerts most of its effects by regulating the activities of various proteins including Ca ²⁺ channels, protein kinases and transcription factors. In plants, studies conducted over the past 10 years...

We characterized the short-term response to waterlogging in Quercus petraea (Matt.) Liebl. and Quercus robur L. as the initial response towards their known long-term differences in tolerance to waterlogging. One-month old seedlings were subjected to hypoxic stress and leaf gas exchange, shoot water potential (Ψs) and root hydraulic conductivity (Lp...

This study aims at estimating the potential of the hydrogen stable isotope (δ2H) analysis of chironomid remains (HC) to reconstruct past changes in the methane (CH4) cycle in lakes. A rearing experiment was first designed to assess the contribution of hydrogen derived from diet to the chironomid biomass and the offset between larvae and their HC. R...

Freshwater lakes are important sources of methane (CH4) emissions, by organic matter degradation under anaerobic conditions (methanogenesis). Previous studies suggest that lakes contribute up to 16 % of natural emissions. About 60 % of the CH4 produced is used as an energy source by methane-oxidizing bacteria (MOB—methanotrophs), which could suppor...

Molecular phylogeny of the oak AQPs. Deduced amino acid sequences from Quercus petraea and (a) sequences of Arabidopsis thaliana or (b) sequences of Populus trichocarpa were used to construct the tree. Maximum likehood phylogenetic analysis and bootstrap test were performed using MEGA 5. Vertical black bars indicate identified subgroups and oak AQP...

Oak AQP results from the TMpred (1) and OCTOPUS (2) servers. PIP2;1 (a), PIP2;2 (b), PIP2;3 (c), PIP1;1 (d), PIP1;2 (e), PIP1;3 (f), TIP2;1 (g), TIP2;2 (h) and TIP1 (i). Helical, membrane-spanning present peaks corresponding with the six major transmembrane domains (indicated by red lines) were predicted using TMpred. Details regarding the length a...

Details of the real-time PCR procedure, including a list of the primers (a) and PCR conditions (b) used in the experiments. (DOC)

Multiple sequence alignment of the predicted amino acid sequences of Quercus petraea and Quercus robur. The sequences were identified from SSH libraries with a representative AQP sequence of Olea europea from the PIP2 (a), PIP1 (b) and TIP (c) subfamilies. The GenBank accession numbers of the protein sequences are as follows: OePIP2;1: DQ202709, Oe...

List of sequences used for phylogenetic analysis. (DOC)

The list of mRNA sequences identified from SSH libraries (a) and details of their use in RACE experiments (b). (DOC)

Details of the six housekeeping genes tested in primary root zones. The sequences were aligned using ClustalW (http://www.ebi.ac.uk/Tools/msa/clustalw2/), and a consensus nucleotide sequence was deduced. The reconstituted sequences account for nucleotide variation, which is likely due to nucleotide variation between Quercus petraea and Quercus robu...

BLASTX results for oak AQPs. cDNAs were compared to cDNAs of other plants. Total score, query coverage and e values are reported. (XLS)

Protein sequence homology between oak AQPs based on isolated cDNAs. Sequence homology was determined using ClustalW (http://www.ebi.ac.uk/Tools/msa/clustalw2/). (DOC)

Basic concepts of NO signalling in animalsNO signalling in plantsInterplays between NO and ROSConclusion AcknowledgementsReferences

Flooding is a common environmental stress inducing a decline in plant growth, development and regeneration. Waterlogging leads to low oxygen levels (hypoxia) in the root environment due to an excess of water in the soil. In response to hypoxia, plants switch their metabolism from aerobic respiration to anaerobic fermentation and can develop morphol...

Plants are constantly exposed to changes in environmental conditions. During periods of stress, the cellular redox homeostasis is altered as a result of reactive oxygen species accumulation. The change in redox is responsible for the symptoms commonly observed during periods of stress and reflects the phytotoxic nature of oxygen radical accumulatio...

L'ennoyage est un phénomène courant qui se répercute sur les végétaux en diminuant leur croissance, leur développement et leur régénération. Il entraîne une forte diminution du taux d'oxygène (hypoxie) dans le compartiment racinaire résultat de l'excès d'eau dans le sol. Face à ce stress, certaines plantes sont capables intensifier leur métabolisme...

Under both natural and agricultural culture conditions, plants are frequently exposed to transient or permanent low O2 levels in the soil atmosphere or soil solution as a consequence of flooding. Thus hypoxia and/or anoxia are environmental stresses commonly encountered by plant root systems. These O2 restriction conditions will have drastic effect...