Search results for "Rh"

Plants and Arbuscular Mycorrhizal Fungi: Cues and Communication in the Early Steps of Symbiotic Interactions

2007

Abstract The ubiquitous nature of arbuscular mycorrhiza (AM) pleads for common molecular and genetic determinants across different plant taxa. The cellular processes determining compatibility in early interactions prior to and during cell contact between arbuscular mycorrhizal fungi and plant roots are starting to be unraveled. The root epidermis is an active checkpoint where signal exchanges and control over root colonization occur. Root‐secreted flavonoids, flavonols, and strigolactones can act as rhizosphere signals in stimulating presymbiotic fungal growth, although their mechanism of action on the fungal cell is as yet unknown. Likewise, fungal signals (Myc factors) activate early plan…

2020

Thorny-headed worms (Acanthocephala) are endoparasites exploiting Mandibulata (Arthropoda) and Gnathostomata (Vertebrata). Despite their world-wide occurrence and economic relevance as a pest, genome and transcriptome assemblies have not been published before. However, such data might hold clues for a sustainable control of acanthocephalans in animal production. For this reason, we present the first draft of an acanthocephalan nuclear genome, besides the mitochondrial one, using the fish parasite Pomphorhynchus laevis (Palaeacanthocephala) as a model. Additionally, we have assembled and annotated the transcriptome of this species and the proteins encoded. A hybrid assembly of long and short…

Remarkable ancient divergences amongst neglected lorisiform primates

2015

Lorisiform primates (Primates: Strepsirrhini: Lorisiformes) represent almost 10% of the living primate species and are widely distributed in sub-Saharan Africa and South/South-East Asia; however, their taxonomy, evolutionary history, and biogeography are still poorly understood. In this study we report the largest molecular phylogeny in terms of the number of represented taxa. We sequenced the complete mitochondrial cytochrome b gene for 86 lorisiform specimens, including ∼80% of all the species currently recognized. Our results support the monophyly of the Galagidae, but a common ancestry of the Lorisinae and Perodicticinae (family Lorisidae) was not recovered. These three lineages have ea…

Genomics of arbuscular mycorrhizal fungi

2004

International audience

A phytosociological analysis of the Olea europaea L. var. sylvestris (Mill.) Lehr. forests in Sicily

2019

This paper presents a phytosociological study on the forest vegetation of Olea europaea var. sylvestris of Sicily and of the smaller minor islands. In Sicily, Oleaster formations show considerable climacic potentiality in the bioclimactic belts between the infra- and the thermomediterranean with single edapho-climacic penetrations that are also in the mesomediterranean; however, these were largely destroyed by man in order to make room for crops. Furthermore, the residual expressions of the Oleaster forests are limited, and often exist as regenerated woodland made possible by the abandonment of agricultural land; they are often small forest nuclei–high maquis, woods and micro-woods–with a m…

PROTECTION FIRST THEN FACILITATION: A MANIPULATIVE PARASITE MODULATES THE VULNERABILITY TO PREDATION OF ITS INTERMEDIATE HOST ACCORDING TO ITS OWN DE…

2011

Many trophically transmitted parasites with complex life cycles manipulate their intermediate host behavior in ways facilitating their transmission to final host by predation. This facilitation generally results from lowering host's antipredatory defenses when the parasite is infective to the final host. However, a recent theoretical model predicts that an optimal parasitic strategy would be to protect the intermediate host from predation when noninfective, before switching to facilitation when the infective stage is reached. We tested this hypothesis in the fish acanthocephalan parasite Pomphorhynchus laevis using the amphipod Gammarus pulex as intermediate host. Gammarids parasitized by n…

Intraspecific conflict over host manipulation between different larval stages of an acanthocephalan parasite

2010

Competitive interactions between coinfecting parasites are expected to be strong when they affect transmission success. When transmission is enhanced by altering host behaviour, intraspecific conflict can lead to ‘coinfection exclusion’ by the first-in parasite or to a ‘sabotage’ of behavioural manipulation by the youngest noninfective parasite. We tested these hypotheses in the acanthocephalan parasite Pomphorhynchus laevis, reversing phototaxis in its intermediate host Gammarus pulex. No evidence was found for coinfection exclusion in gammarids sequentially exposed to infection. Behavioural manipulation was slightly weakened but not cancelled in gammarids infected with mixed larval stages…

Arbuscular mycorrhiza induced ATPases and membrane nutrient transport mechanisms

2002

The evolutionary success of arbuscular mycorrhizal (AM) symbiosis reflects the unique combination of a superior biotrophic mode of fungal carbon acquisition and the ability of the living plant to absorb nutrients, especially phosphorus, from the fungal partner (Jakobsen 1999). This mutualistic way of life must require controlled expression of a large set of membrane transport systems active in phosphate uptake from the soil by the extraradical hyphae, its transfer to the host plant across a symbiotic interface, and coupled to transport of photosynthates in the opposite direction. The implied membrane transporters are therefore integral systems in the functioning of the symbiosis. Very littl…

Plant genes involved in arbuscular mycorrhiza formation and functioning

2002

Knowledge about that part of the plant genome involved in the establishment and functioning of the arbuscular mycorrhizal (AM) symbiosis is important for the basic understanding of this symbiosis. It is also essential for a ‘genes to the field’ approach based on the identification and exploitation of genes that could be central to developing sustainable plant production systems in the future.

Response Mechanisms of Invertebrates to Bacillus thuringiensis and Its Pesticidal Proteins

2021

SUMMARY Extensive use of chemical insecticides adversely affects both environment and human health. One of the most popular biological pest control alternatives is bioinsecticides based on Bacillus thuringiensis. This entomopathogenic bacterium produces different protein types which are toxic to several insect, mite, and nematode species. Currently, insecticidal proteins belonging to the Cry and Vip3 groups are widely used to control insect pests both in formulated sprays and in transgenic crops. However, the benefits of B. thuringiensis-based products are threatened by insect resistance evolution. Numerous studies have highlighted that mutations in genes coding for surrogate receptors are …