Search results for "OTA"
showing 10 items of 33012 documents
Changes in lipid and carotenoid metabolism in Chlamydomonas reinhardtii during induction of CO2-concentrating mechanism: Cellular response to low CO2…
2020
Photosynthetic organisms strictly depend on CO2 availability and the CO2:O2 ratio, as both CO2/O2 compete for catalytic site of Rubisco. Green alga Chlamydomonas reinhardtii, can overcome CO2 shortage by inducing CO2-concentrating mechanism (CCM). Cells transferred to low-CO2 are subjected to light-driven oxidative stress due to decrease in the electron sink. Response to environmental perturbations is mediated to some extent by changes in the lipid and carotenoid metabolism. We thus hypothesize that when cells are challenged with changes in CO2 availability, changes in the lipidome and carotenoids profile occur. These changes expected to be transient, when CCM is activated, CO2 limitation w…
Extraction and Analysis of Carotenoids from Escherichia coli in Color Complementation Assays
2017
A common method to investigate the function of genes putatively involved in carotenoid biosynthesis is the so called color complementation assay in Escherichia coli (see, e.g., Cunningham and Gantt, 2007). In this assay, the gene under investigation is expressed in E. coli strains genetically engineered to synthesize potential carotenoid substrates, followed by analysis of the pigment changes in the carotenogenic bacteria via high-performance liquid chromatography (HPLC). Two crucial steps in this method are (i) the quantitative extraction of the carotenoids out of E. coli and (ii) the reproducible and complete separation of the pigments by HPLC. Here, we present a protocol for the extracti…
The Role of Phospholipase D and MAPK Signaling Cascades in the Adaption of Lichen Microalgae to Desiccation: Changes in Membrane Lipids and Phosphopr…
2016
Classically, lichen phycobionts are described as poikilohydric organisms able to undergo desiccation due to the constitutive presence of molecular protection mechanisms. However, little is known about the induction of cellular responses in lichen phycobionts during drying. The analysis of the lipid composition of the desiccated lichen microalga Asterochloris erici revealed the unusual accumulation of highly polar lipids (oligogalactolipids and phosphatidylinositol), which prevents the fusion of membranes during stress, but also the active degradation of cone-shaped lipids (monogalactosyldiacylglycerol and phosphatidylethanolamine) to stabilize membranes in desiccated cells. The level of pho…
Expression of miR159 Is Altered in Tomato Plants Undergoing Drought Stress.
2019
In a scenario of global climate change, water scarcity is a major threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in many plant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and …
Unravelling the biosynthesis of pyriculol in the rice blast fungus Magnaporthe oryzae
2017
Pyriculol was isolated from the rice blast fungus Magnaporthe oryzae and found to induce lesion formation on rice leaves. These findings suggest that it could be involved in virulence. The gene MoPKS19 was identified to encode a polyketide synthase essential for the production of the polyketide pyriculol in the rice blast fungus M. oryzae. The transcript abundance of MoPKS19 correlates with the biosynthesis rate of pyriculol in a time-dependent manner. Furthermore, gene inactivation of MoPKS19 resulted in a mutant unable to produce pyriculol, pyriculariol and their dihydro derivatives. Inactivation of a putative oxidase-encoding gene MoC19OXR1, which was found to be located in the genome cl…
Ageing via perception costs of reproduction magnifies sexual selection.
2018
Understanding what factors modulate sexual selection intensity is crucial to a wide variety of evolutionary processes. Recent studies show that perception of sex pheromones can severely impact male mortality when it is not followed by mating (perception costs of reproduction). Here, we examine the idea that this may magnify sexual selection by further decreasing the fitness of males with inherently low mating success, hence increasing the opportunity for sexual selection. We use mathematical modelling to show that even modest mortality perception costs can significantly increase variability in male reproductive success under a wide range of demographic conditions. We then conduct a series …
Direct and correlated responses to bi-directional selection on pre-adult development time in Drosophila montana.
2019
Selection experiments offer an efficient way to study the evolvability of traits that play an important role in insects’ reproduction and/or survival and to trace correlations and trade-offs between them. We have exercised bi-directional selection on Drosophila montana flies’ pre-adult development time under constant light and temperature conditions for 10 generations and traced the indirect effects of this selection on females’ diapause induction under different day lengths, as well as on the body weight and cold tolerance of both sexes. Overall, selection was successful towards slow, but not towards fast development. However, all fast selection line replicates showed at the end of selecti…
Personality, immune response and reproductive success: an appraisal of the pace-of-life syndrome hypothesis.
2017
11 pages; International audience; The pace-of-life syndrome (POLS) hypothesis is an extended concept of the life-history theory that includes behavioural traits. The studies challenging the POLS hypothesis often focus on the relationships between a single personality trait and a physiological and/or life-history trait. While pathogens represent a major selective pressure, few studies have been interested in testing relationships between behavioural syndrome, and several fitness components including immunity. The aim of this study was to address this question in the mealworm beetle, Tenebrio molitor, a model species in immunity studies. The personality score was estimated from a multidimensi…
Transcriptomic responses to biotic stresses in Malus x domestica: a meta-analysis study.
2017
AbstractRNA-Seq analysis is a strong tool to gain insight into the molecular responses to biotic stresses in plants. The objective of this work is to identify specific and common molecular responses between different transcriptomic data related to fungi, virus and bacteria attacks in Malus x domestica. We analyzed seven transcriptomic datasets in Malus x domestica divided in responses to fungal pathogens, virus (Apple Stem Grooving Virus) and bacteria (Erwinia amylovora). Data were dissected using an integrated approach of pathway- and gene- set enrichment analysis, Mapman visualization tool, gene ontology analysis and inferred protein-protein interaction network. Our meta-analysis revealed…
Gaining Insight into Exclusive and Common Transcriptomic Features Linked with Biotic Stress Responses in Malus
2017
Identifying key information in transcriptomic data is very important, especially when the “omic” study deals with plant responses to stresses in field conditions where a high number of variables and disturbing factors may affect the analysis. In this meta-analysis we collected 12 transcriptomic works in Malus in order to identify which key genes, proteins, gene categories are involved in general plant pathological conditions and those features linked with exclusive biotic stress responses. Those genes that are only related with molecular responses to pathogen attacks and those linked with other plant physiological processes were identified. A pipeline composed by pathway and gene set enrich…