Transcriptomic analysis reveals the gene regulatory networks involved in leaf and root response to osmotic stress in tomato

IntroductionTomato (Solanum lycopersicum L.) is a major horticultural crop that is cultivated worldwide and is characteristic of the Mediterranean agricultural system. It represents a key component of the diet of billion people and an important source of vitamins and carotenoids. Tomato cultivation in open field often experiences drought episodes, leading to severe yield losses, since most modern cultivars are sensitive to water deficit. Water stress leads to changes in the expression of stress-responsive genes in different plant tissues, and transcriptomics can support the identification of genes and pathways regulating this response. MethodsHere, we performed a transcriptomic analysis of two tomato genotypes, M82 and Tondo, in response to a PEG-mediated osmotic treatment. The analysis was conducted separately on leaves and roots to characterize the specific response of these two organs. ResultsA total of 6,267 differentially expressed transcripts related to stress response was detected. The construction of gene co-expression networks defined the molecular pathways of the common and specific responses of leaf and root. The common response was characterized by ABA-dependent and ABA-independent signaling pathways, and by the interconnection between ABA and JA signaling. The root-specific response concerned genes involved in cell wall metabolism and remodeling, whereas the leaf-specific response was principally related to leaf senescence and ethylene signaling. The transcription factors representing the hubs of these regulatory networks were identified. Some of them have not yet been characterized and can represent novel candidates for tolerance. DiscussionThis work shed new light on the regulatory networks occurring in tomato leaf and root under osmotic stress and set the base for an in-depth characterization of novel stress-related genes that may represent potential candidates for improving tolerance to abiotic stress in tomato

Unusual Domestic Source of Lead Poisoning

Non-occupational lead poisoning is not rare, mainly occurring in domestic situations in children, but also in adults. Lead poisoning was observed in a 65 years-old woman non-exposed to risk that caught our attention with a diagnostic suspicion of acute intermittent porphyria according to recurrent episodes of abdominal pain and neuropathy of upper limbs. Acute intermittent porphyria was excluded by a laboratory investigation that showed instead severe lead poisoning. After several thorough examinations of the domestic environment, the source of intoxication has been detected in some cooking pots that released high concentrations of lead. Ethylenediamine tetracetic acid disodium calcium therapy (three cycles) reduced consistently blood lead concentration and, after one year, neuropathy was almost entirely recovered

Le g(ne MIP Un mutant nucl aire d ficient dans l'activit DNA polym rasique mitochondriale chez Saccharomyces cerevisiae

SIGLEBSE B226286C / UCL - Université Catholique de LouvainBEBelgiu

Transcriptional basis of drought-induced susceptibility to the rice blast fungus Magnaporthe oryzae

Plants are often facing several stresses simultaneously. Understanding how they reactand the way pathogens adapt to such combinational stresses is poorly documented.Here, we developed an experimental system mimicking field intermittent drought onrice followed by inoculation by the pathogenic fungus Magnaporthe oryzae. Thisexperimental system triggers an enhancement of susceptibility that could be correlatedwith the dampening of several aspects of plant immunity, namely the oxidative burst andthe transcription of several pathogenesis-related genes. Quite strikingly, the analysisof fungal transcription by RNASeq analysis under drought reveals that the fungus isgreatly modifying its virulence program: genes coding for small secreted proteins weremassively repressed in droughted plants compared to unstressed ones whereas genescoding for enzymes involved in degradation of cell-wall were induced. We also showthat drought can lead to the partial breakdown of several major resistance genes byaffecting R plant gene and/or pathogen effector expression.We propose a model wherea yet unknown plant signal can trigger a change in the virulence program of the pathogento adapt to a plant host that was affected by drought prior to infection

Detection of drought events using combination of satellite data and soil moisture modelling

The use of satellite data offers a potentially well usable tool to accurate drought monitoring. The study examines the space-time possibility of agricultural drought detection using freely available data from the MODIS instrument onboard Terra and Aqua satellites that reflects vegetation condition. Vegetation greenness metrics used in this study are based on the spectral reflectance curves in the visible red and near-infrared part of the spectrum and are expressed in relation to the average for the period of 2000-2014. The results are presented in weekly time step for the whole area of the Czech Republic, and are compared to the drought monitor system, based on the SoilClim dynamic model for soil water content estimates. These data, as well as other parameters, such as soil properties and land use, are integrated at 500 meters spatial resolution