Search results for "class"

Cultivar- and Wood Area-Dependent Metabolomic Fingerprints of Grapevine Infected by Botryosphaeria Dieback

2020

International audience; Botryosphaeria dieback is one of the most significant grapevine trunk diseases that affects the sustainability of the vineyards and provokes economic losses. The causal agents, Botryosphaeriaceae species, live in and colonize the wood of the perennial organs causing wood necrosis. Diseased vines show foliar symptoms, chlorosis, or apoplexy, associated to a characteristic brown stripe under the bark. According to the susceptibility of the cultivars, specific proteins such as PR-proteins and other defense-related proteins are accumulated in the brown stripe compared with the healthy woody tissues. In this study, we enhanced the characterization of the brown stripe and …

How ants acclimate: Impact of climatic conditions on the cuticular hydrocarbon profile

2017

1.Organisms from temperate zones are exposed to seasonal changes and must be able to cope with a wide range of climatic conditions. Especially ectotherms, including insects, are at risk to desiccate under dry and warm conditions, the more so given the changing climate. 2.To adjust to current conditions, organisms acclimate through changes in physiology, morphology and/or behaviour. Insects protect themselves against desiccation through a layer of cuticular hydrocarbons (CHC) on their body surface. Hence, acclimation may also affect the CHC profile, changing their waterproofing capacity under different climatic conditions. 3.Here, we investigated the acclimation response of two Temnothorax a…

Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways

2015

The red palm weevil (RPW; Rhynchophorus ferrugineus) is spreading worldwide and severely harming many palm species. However, most studies on RPW focused on insect biology, and little information is available about the plant response to the attack. In the present experiment, we used metabolomics to study the alteration of the leaf metabolome of Phoenix canariensis at initial (1st stage) or advanced (2nd stage) attack by RPW compared with healthy (unattacked) plants. The leaf metabolome significantly varied among treatments. At the 1st stage of attack, plants showed a reprogramming of carbohydrate and organic acid metabolism; in contrast, peptides and lipid metabolic pathways underwent more c…

Underestimated regional species diversity in the Cape Floristic Region revealed by phylogenetic analysis of the Erica abietina/E. viscaria clade (Eri…

2017

Synthesis of Isomaltooligosaccharides by Saccharomyces cerevisiae Cells Expressing Aspergillus niger α‑Glucosidase

2017

The α-glucosidase encoded by the aglA gene of Aspergillus niger is a secreted enzyme belonging to family 31 of glycoside hydrolases. This enzyme has a retaining mechanism of action and displays transglycosylating activity that makes it amenable to be used for the synthesis of isomaltooligosaccharides (IMOs). We have expressed the aglA gene in Saccharomyces cerevisiae under control of a galactose-inducible promoter. Recombinant yeast cells expressing the aglA gene produced extracellular α-glucosidase activity about half of which appeared cell bound whereas the other half was released into the culture medium. With maltose as the substrate, panose is the main transglycosylation product after 8…

Evidence for Succession and Putative Metabolic Roles of Fungi and Bacteria in the Farming Mutualism of the Ambrosia Beetle Xyleborus affinis.

2020

The bacterial and fungal community involved in ambrosia beetle fungiculture remains poorly studied compared to the famous fungus-farming ants and termites. Here we studied microbial community dynamics of laboratory nests, adults, and brood during the life cycle of the sugarcane shot hole borer, Xyleborus affinis. We identified a total of 40 fungal and 428 bacterial operational taxonomic units (OTUs), from which only five fungi (a Raffaelea fungus and four ascomycete yeasts) and four bacterial genera (Stenotrophomonas, Enterobacter, Burkholderia, and Ochrobactrum) can be considered the core community playing the most relevant symbiotic role. Both the fungal and bacterial populations varied s…

2020

During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expa…

First extensive characterization of the venom gland from an egg parasitoid: structure, transcriptome and functional role.

2018

The venom gland is a ubiquitous organ in Hymenoptera. In insect parasitoids, the venom gland has been shown to have multiple functions including regulation of host immune response, host paralysis, host castration and developmental alteration. However, the role played by the venom gland has been mainly studied in parasitoids developing in larval or pupal hosts while little is known for parasitoids developing in insect eggs. We conducted the first extensive characterization of the venom of the endoparasitoid Ooencyrtus telenomicida (Vassiliev), a species that develops in eggs of the stink bug Nezara viridula (L.). In particular we investigated the structure of the venom apparatus, its functio…

Oxylipin mediated stress response of a miraculin-like protease inhibitor in Hexanoic acid primed eggplant plants infested by Colorado potato beetle

2017

Insect-plant interactions are governed by a complex equilibrium between the mechanisms through which plant recognize insect attack and orchestrate downstream signaling events that trigger plant defense responses, and the mechanisms by which insects overcome plant defenses. Due to this tight and dynamic interplay, insight into the nature of the plant defense response can be gained by analyzing changes in the insect herbivores digestive system upon plant feeding. In this work we have identified a Solanum melongena miraculin-like protease inhibitor in the midgut juice of Colorado potato larvae feeding on eggplant plants treated with the natural inducer of plant defenses hexanoic acid. We analy…

Extended winters entail long-term costs for insect offspring reared in an overwinter burrow

2018

International audience; Winter imposes an ecological challenge to animals living in colder climates, especially if these adverse conditions coincide with reproduction and offspring rearing. To overcome this challenge, some insects burrow in the soil to protect adults, larvae, or eggs from negative effects of winter. However, whether this protection is effective against any long-term consequences of changes in winter duration is unclear. Here, we investigated the long-term effects of winter length variation on eggs of the European earwig Forficula auricularia. In this insect, females construct and maintain a burrow between late autumn and spring, in which they provide extensive forms of care…