Search results for "DAC"

Neonicotinoids in excretion product of phloem-feeding insects kill beneficial insects

2019

Significance The use of insecticides in agriculture is one of the suggested causes of the decline in insect populations. Neonicotinoids are among the most widely used insecticides. However, they have important negative side effects, especially for pollinators and other beneficial insects feeding on floral nectar and pollen. We identified an exposure route: Neonicotinoids reach and kill beneficial insects when they feed on the most abundant carbohydrate source for insects in agroecosystems, honeydew. Honeydew is the excretion product of phloem-feeding hemipteran insects such as aphids, mealybugs, whiteflies, or psyllids. This route of exposure is likely to affect a much wider range of benefi…

Type 2 histone deacetylases play a major role in the control of elicitor-induced cell death in tobacco

2011

article addendum : Bourque S, Dutartre A, Hammoudi V, Blanc S, Dahan J, Jeandroz S, Pichereaux C, Rossignol M, Wendehenne D., 2011. Type-2 histone deacetylases as new regulators of elicitorinduced cell death in plants. New Phytologist, 192 (1), 127–139. DOI: 10.1111/j.1469-8137.2011.03788.x; International audience; The cell death which characterizes the onset of the Hypersensitive Response (HR) is a very important weapon evolved by plants to block pathogen development. By the use of numerous plant/avirulent pathogen or plant/elicitor models, we have now obtained detailed signalling pathways allowing, after pathogen or elicitor perception, the control of the expression of specific sets of ge…

Trophic interactions between introduced lake trout (Salvelinus namaycush) and native Arctic charr (S. alpinus) in a large Fennoscandian subarctic lake

2014

Introduced fishes may have major impacts on community structure and ecosystem function due to competitive and predatory interactions with native species. For example, introduced lake trout (Salvelinus namaycush) has been shown to replace native salmonids and induce major trophic cascades in some North American lakes, but few studies have investigated trophic interactions between lake trout and closely related native Arctic charr (S.alpinus) outside the natural distribution of the former species. We used stomach content and stable isotope analyses to investigate trophic interactions between introduced lake trout and native Arctic charr in large subarctic Lake Inarijarvi in northern Finland. …

Why ruminating ungulates chew sloppily: Biomechanics discern a phylogenetic pattern.

2019

Altres ajuts: "Beatriu de Pinos" 2014 - BP-A 00048 There is considerable debate regarding whether mandibular morphology in ungulates primarily reflects phylogenetic affinities or adaptation to specific diet. In an effort to help resolve this debate, we use three-dimensional finite element analysis (FEA) to assess the biomechanical performance of mandibles in eleven ungulate taxa with well-established but distinct dietary preferences. We found notable differences in the magnitude and the distribution of von Mises stress between Artiodactyla and Perissodactyla, with the latter displaying lower overall stress values. Additionally, within the order Artiodactyla the suborders Ruminantia and Tylo…

Molecular evidence supports simultaneous association of the achlorophyllous orchid Chamaegastrodia inverta with ectomycorrhizal Ceratobasidiaceae and…

2020

Abstract Background Achlorophyllous orchids are mycoheterotrophic plants, which lack photosynthetic ability and associate with fungi to acquire carbon from different environmental sources. In tropical latitudes, achlorophyllous forest orchids show a preference to establish mycorrhizal relationships with saprotrophic fungi. However, a few of them have been recently found to associate with ectomycorrhizal fungi and there is still much to be learned about the identity of fungi associated with tropical orchids. The present study focused on mycorrhizal diversity in the achlorophyllous orchid C. inverta, an endangered species, which is endemic to southern China. The aim of this work was to identi…

A new flatworm species of Temnocephala (Rhabdocoela, Temnocephalidae) ectosymbiont on the freshwater crab Valdivia serrata (Decapoda, Trichodactylida…

2020

A new species of temnocephalan is described from the branchial chambers ofValdivia serratain Colombia asTemnocephala ivandarioisp. nov.The most distinctive characters of the new species are in the cirrus and the epidermal ‘excretory’ syncytial plates. In the present study, the terminology to describe the cirrus of species ofTemnocephalais updated. Comparison between the shape of the cirrus of the temnocephalans associated with trichodactylid crabs is also provided.

Plant species identities and fertilization influence on arbuscular mycorrhizal fungal colonisation and soil bacterial activities

2016

International audience; Plant species influence soil microbial communities, mainly through their functional traits. However, mechanisms underlying these effects are not well understood, and in particular how plant/ microorganism interactions are affected by plant identities and/or environmental conditions. Here, we performed a greenhouse experiment to assess the effects of three plant species on arbuscular mycorrhizal fungal (AMF) colonization, bacterial potential nitrification (PNA) and denitrification activities (PDA) through their functional traits related to nitrogen acquisition and turnover. Three species with contrasting functional traits and strategies (from exploitative to conservat…

Notas taxonómicas y distributivas sobre <em>Serapias lingua</em> subsp. <em>tunetana</em> (Orchidaceae), una rara espècie end…

2019

Serapias lingua subsp. tunetana, una rara orquídea endémica con área de distribución restringida en Túnez, al norte de Túnez, ha sido redescubierta lejos de su localidad tipo después de 22 años. Desde su primer hallazgo en 1996 y su descripción publicada en 2005, la subespecie no se había encontrado nuevamente y se presume que se extinguió o fue identificada erróneamente. En este trabajo se proporciona una descripción detallada de la subespecie que justifica una enmienda a su descripción, y se aporta asimismo un mapa de distribución y varias fotografías. Se listan las principales afinidades de la subsp. tunetana con los táxones más estrechamente relacionados dentro del grupo de S. lingua qu…

2016

Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachin…

A Revision of Sesuvium (Aizoaceae, Sesuvioideae)

2017

Sesuvium and Cypselea are closely related succulent genera within the Sesuvioideae (Aizoaceae). Since Cypselea is nested in Sesuvium in molecular studies and both genera share traits separating them from other members of the subfamily, we propose to include Cypselea in Sesuvium. Sesuvium (incl. Cypselea) comprises 14 species and is distributed worldwide with centres of diversity in southern Africa and North and Central America. Sesuvium comprises erect to procumbent herbs with opposite leaves that often bear conspicuous sheath-like lateral appendages on the petioles (pseudostipules). These and the many-seeded capsules are diagnostic traits, separating Sesuvium from the closely related gener…