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11.
Aline Planchon Gaëlle Durambur Jean‐Baptiste Besnier Carole Plasson Bruno Gügi Sophie Bernard Annabelle Mrieau Jean‐Paul Trouv Caroline Dubois Karine Laval Azeddine Driouich Jean‐Claude Mollet Richard Gattin 《Plant, cell & environment》2021,44(1):304-322
In Normandy, flax is a plant of important economic interest because of its fibres. Fusarium oxysporum, a telluric fungus, is responsible for the major losses in crop yield and fibre quality. Several methods are currently used to limit the use of phytochemicals on crops. One of them is the use of plant growth promoting rhizobacteria (PGPR) occurring naturally in the rhizosphere. PGPR are known to act as local antagonists to soil‐borne pathogens and to enhance plant resistance by eliciting the induced systemic resistance (ISR). In this study, we first investigated the cell wall modifications occurring in roots and stems after inoculation with the fungus in two flax varieties. First, we showed that both varieties displayed different cell wall organization and that rapid modifications occurred in roots and stems after inoculation. Then, we demonstrated the efficiency of a Bacillus subtilis strain to limit Fusarium wilt on both varieties with a better efficiency for one of them. Finally, thermo‐gravimetry was used to highlight that B. subtilis induced modifications of the stem properties, supporting a reinforcement of the cell walls. Our findings suggest that the efficiency and the mode of action of the PGPR B. subtilis is likely to be flax variety dependent. 相似文献
12.
Goutam Chandra Sen Chandra Sreetama Davi A.G. Mzala Karine Charton Jack H. VanderMeulen Isabelle Richard Jyoti K. Jaiswal 《The Journal of cell biology》2021,220(5)
Of the many crucial functions of the ER, homeostasis of physiological calcium increase is critical for signaling. Plasma membrane (PM) injury causes a pathological calcium influx. Here, we show that the ER helps clear this surge in cytoplasmic calcium through an ER-resident calcium pump, SERCA, and a calcium-activated ion channel, Anoctamin 5 (ANO5). SERCA imports calcium into the ER, and ANO5 supports this by maintaining electroneutrality of the ER lumen through anion import. Preventing either of these transporter activities causes cytosolic calcium overload and disrupts PM repair (PMR). ANO5 deficit in limb girdle muscular dystrophy 2L (LGMD2L) patient cells compromises their cytosolic and ER calcium homeostasis. By generating a mouse model of LGMD2L, we find that PM injury causes cytosolic calcium overload and compromises the ability of ANO5-deficient myofibers to repair. Addressing calcium overload in ANO5-deficient myofibers enables them to repair, supporting the requirement of the ER in calcium homeostasis in injured cells and facilitating PMR. 相似文献
13.
Immigration is a major demographic parameter shaping population dynamics and is an important driver of eco‐evolutionary patterns, but the fitness consequences for individuals following their settlement to a new population (immigrants) remain poorly tested in wild animal populations, particularly among long‐lived species. Here we show that immigrants have a lower fitness than residents in three wild seabird populations (wandering albatross Diomedea exulans, southern fulmar Fulmarus glacialoides, snow petrel Pagodroma nivea). Across all species and during a 32‐year period, immigrants made on average ?9 to 29% fewer breeding attempts, had 5–31% fewer fledglings, had 2–16% lower breeding success and produced 6–46% fewer recruits. Female immigration and male residency were also favored through differences in breeding performance. We provide evidence for selection against immigrants in wild populations of long‐lived species and our results are consistent with female‐biased dispersal in birds being driven by asymmetric limiting resources and the competitive ability of dispersers vs. non‐dispersers. 相似文献
14.
Karine Lambou Andrea Pennati Isabel Valsecchi Rui Tada Stephen Sherman Hajime Sato Remi Beau Giovanni Gadda Jean-Paul Latgé 《Eukaryotic cell》2013,12(6):853-863
The choline oxidase (CHOA) and betaine aldehyde dehydrogenase (BADH) genes identified in Aspergillus fumigatus are present as a cluster specific for fungal genomes. Biochemical and molecular analyses of this cluster showed that it has very specific biochemical and functional features that make it unique and different from its plant and bacterial homologs. A. fumigatus ChoAp catalyzed the oxidation of choline to glycine betaine with betaine aldehyde as an intermediate and reduced molecular oxygen to hydrogen peroxide using FAD as a cofactor. A. fumigatus Badhp oxidized betaine aldehyde to glycine betaine with reduction of NAD+ to NADH. Analysis of the AfchoAΔ::HPH and AfbadAΔ::HPH single mutants and the AfchoAΔAfbadAΔ::HPH double mutant showed that AfChoAp is essential for the use of choline as the sole nitrogen, carbon, or carbon and nitrogen source during the germination process. AfChoAp and AfBadAp were localized in the cytosol of germinating conidia and mycelia but were absent from resting conidia. Characterization of the mutant phenotypes showed that glycine betaine in A. fumigatus functions exclusively as a metabolic intermediate in the catabolism of choline and not as a stress protectant. This study in A. fumigatus is the first molecular, cellular, and biochemical characterization of the glycine betaine biosynthetic pathway in the fungal kingdom. 相似文献
15.
Global Analysis of Apicomplexan Protein S‐Acyl Transferases Reveals an Enzyme Essential for Invasion
Karine Frénal Chwen L. Tay Christina Mueller Ellen S. Bushell Yonggen Jia Arnault Graindorge Oliver Billker Julian C. Rayner Dominique Soldati‐Favre 《Traffic (Copenhagen, Denmark)》2013,14(8):895-911
The advent of techniques to study palmitoylation on a whole proteome scale has revealed that it is an important reversible modification that plays a role in regulating multiple biological processes. Palmitoylation can control the affinity of a protein for lipid membranes, which allows it to impact protein trafficking, stability, folding, signalling and interactions. The publication of the palmitome of the schizont stage of Plasmodium falciparum implicated a role for palmitoylation in host cell invasion, protein export and organelle biogenesis. However, nothing is known so far about the repertoire of protein S‐acyl transferases (PATs) that catalyse this modification in Apicomplexa. We undertook a comprehensive analysis of the repertoire of Asp‐His‐His‐Cys cysteine‐rich domain (DHHC‐CRD) PAT family in Toxoplasma gondii and Plasmodium berghei by assessing their localization and essentiality. Unlike functional redundancies reported in other eukaryotes, some apicomplexan‐specific DHHCs are essential for parasite growth, and several are targeted to organelles unique to this phylum. Of particular interest is DHHC7, which localizes to rhoptry organelles in all parasites tested, including the major human pathogen P. falciparum. TgDHHC7 interferes with the localization of the rhoptry palmitoylated protein TgARO and affects the apical positioning of the rhoptry organelles. This PAT has a major impact on T. gondii host cell invasion, but not on the parasite's ability to egress. 相似文献
16.
17.
Karine Monceau Mariangela Arca Lisa Leprêtre Florence Mougel Olivier Bonnard Jean-Fran?ois Silvain Nevile Maher Gérard Arnold Denis Thiéry 《PloS one》2013,8(6)
Contrary to native predators, which have co-evolved with their prey, alien predators often benefit from native prey naïveté. Vespa velutina, a honeybee predator originating from Eastern China, was introduced into France just before 2004. The present study, based on video recordings of two beehives at an early stage of the invasion process, intends to analyse the alien hornet hunting behaviour on the native prey, Apis mellifera, and to understand the interaction between the activity of the predator and the prey during the day and the season. Chasing hornets spent most of their time hovering facing the hive, to catch flying honeybees returning to the hive. The predation pressure increased during the season confirming previous study based on predator trapping. The number of honeybee captures showed a maximum peak for an intermediate number of V. velutina, unrelated to honeybee activity, suggesting the occurrence of competition between hornets. The number of honeybees caught increased during midday hours while the number of hornets did not vary, suggesting an increase in their efficacy. These results suggest that the impact of V. velutina on honeybees is limited by its own biology and behaviour and did not match the pattern of activity of its prey. Also, it could have been advantageous during the invasion, limiting resource depletion and thus favouring colonisation. This lack of synchronization may also be beneficial for honeybee colonies by giving them an opportunity to increase their activity when the hornets are less effective. 相似文献
18.
Caribbean avifaunal biogeography has been mainly studied based on mitochondrial DNA. Here, we investigated both past and recent island differentiation and micro-evolutionary changes in the Zenaida Dove (Zenaida aurita) based on combined information from one mitochondrial (Cytochrome c Oxydase subunit I, COI) and 13 microsatellite markers and four morphological characters. This Caribbean endemic and abundant species has a large distribution, and two subspecies are supposed to occur: Z. a. zenaida in the Greater Antilles (GA) and Z. a. aurita in the Lesser Antilles (LA). Doves were sampled on two GA islands (Puerto Rico and the British Virgin Islands) and six LA islands (Saint Barthélemy, Guadeloupe, Les Saintes, Martinique, Saint Lucia and Barbados). Eleven COI haplotypes were observed that could be assembled in two distinct lineages, with six specific to GA, four to LA, the remaining one occurring in all islands. However, the level of divergence between those two lineages was too moderate to fully corroborate the existence of two subspecies. Colonisation of the studied islands appeared to be a recent process. However, both phenotypic and microsatellite data suggest that differentiation is already under way between all of them, partly associated with the existence of limited gene flow. No isolation by distance was observed. Differentiation for morphological traits was more pronounced than for neutral markers. These results suggest that despite recent colonisation, genetic drift and/or restricted gene flow are promoting differentiation for neutral markers. Variation in selective pressures between islands may explain the observed phenotypic differentiation. 相似文献
19.
Camila Gewehr Sara Marchesan Oliveira Mateus Fortes Rossato Gabriela Trevisan Gerusa Duarte Dalmolin Flávia Karine Rigo Célio José de Castro Júnior Marta Nascimento Cordeiro Juliano Ferreira Marcus V. Gomez 《PLoS neglected tropical diseases》2013,7(4)
Background
The frequency of accidental spider bites in Brazil is growing, and poisoning due to bites from the spider genus Phoneutria nigriventer is the second most frequent source of such accidents. Intense local pain is the major symptom reported after bites of P. nigriventer, although the mechanisms involved are still poorly understood. Therefore, the aim of this study was to identify the mechanisms involved in nociception triggered by the venom of Phoneutria nigriventer (PNV).Methodology/Principal Findings
Twenty microliters of PNV or PBS was injected into the mouse paw (intraplantar, i.pl.). The time spent licking the injected paw was considered indicative of the level of nociception. I.pl. injection of PNV produced spontaneous nociception, which was reduced by arachnid antivenin (ArAv), local anaesthetics, opioids, acetaminophen and dipyrone, but not indomethacin. Boiling or dialysing the venom reduced the nociception induced by the venom. PNV-induced nociception is not dependent on glutamate or histamine receptors or on mast cell degranulation, but it is mediated by the stimulation of sensory fibres that contain serotonin 4 (5-HT4) and vanilloid receptors (TRPV1). We detected a kallikrein-like kinin-generating enzyme activity in tissue treated with PNV, which also contributes to nociception. Inhibition of enzymatic activity or administration of a receptor antagonist for kinin B2 was able to inhibit the nociception induced by PNV. PNV nociception was also reduced by the blockade of tetrodotoxin-sensitive Na+ channels, acid-sensitive ion channels (ASIC) and TRPV1 receptors.Conclusion/Significance
Results suggest that both low- and high-molecular-weight toxins of PNV produce spontaneous nociception through direct or indirect action of kinin B2, TRPV1, 5-HT4 or ASIC receptors and voltage-dependent sodium channels present in sensory neurons but not in mast cells. Understanding the mechanisms involved in nociception caused by PNV are of interest not only for better treating poisoning by P. nigriventer but also appreciating the diversity of targets triggered by PNV toxins. 相似文献20.
Karine Briot Simon Paternotte Sami Kolta Richard Eastell Dieter Felsenberg David M. Reid Claus-C. Glüer Christian Roux 《PloS one》2013,8(12)