Search results for "Race"

Phylogeny, biogeography, and chromosome evolution of the amphitropical genus Grindelia (Asteraceae) inferred from nuclear ribosomal and chloroplast s…

2012

Typification of the Linnaean name Ambrosinia bassii and other nomenclatural remarks in the genus Ambrosinia (Araceae)

2018

Although Ferdinando Bassi is the nomenclatural authority for the genus Ambrosina, the correct spelling of the name should be the Linnaean “Ambrosinia”. A lectotype is designated for A. bassii, the only species currently recognized. In addition, two lectotypes, two epitypes and one neotype are designated for other names of taxa currently treated within the infra-specific variability of A. bassii.

Shimia thalassica sp. nov., and reclassification of Pseudopelagicola gijangensis as Shimia gijangensis comb. nov., and Thalassobius activus as Cognat…

2019

Strain CECT 7735T, a marine Gram-reaction negative, aerobic, non-motile bacterium, was isolated from coastal seawater in Valencia, Spain. Strain CECT 7735T is chemoorganotrophic, mesophilic, slightly halophilic, grows at 15–28 °C but not at 4 or 37 °C, requires seawater for growth and grows up to 6 % salinity. The major cellular fatty acid is summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The G+C content of the genome is 55.7 mol%. Comparative analysis of the 16S rRNA gene sequence shows the strain is affiliated to the family Rhodobacteraceae , in the class Alphaproteobacteria , with highest similarities to Phaeobacter species (97.0–97.5 %), Shimia species (96.5–97.3 %) and Pseudopelagico…

Kindness to the final host and vice versa: A trend for parasites providing easy prey?

2019

Traditionally the “extended phenotype” concept refers to parasites that manipulate host phenotype to increase parasite fitness. This includes parasites that render intermediate hosts more susceptible to predation by final hosts. We explore here the proposition that an evolutionary driver in such cases is the energetic benefit to the final host, in addition to increased parasite fitness. We will review some well-established host-manipulation models, where such a scenario seems likely. One example is provided by the protozoan Toxoplasma gondii, which conspicuously impairs predator avoidance in rodents. Pathologies in humans that acquire T. gondii are known, but infection in adult feline defin…

Calcium—Nutrient and Messenger

2019

Calcium is an essential element needed for growth and development of plants under both non-stressed and stress conditions. It thereby fulfills a dual function, being not only an important factor for cell wall and membrane stability, but also serving as a second messenger in many developmental and physiological processes, including the response of plants to biotic stress. The perception of non-self hereby induces an influx of calcium ions (Ca2+) into the cytosol, which is decoded into downstream responses ultimately leading to defense. Maintaining intracellular Ca2+ homeostasis is crucial for the ability to generate this signal. This review will describe the current knowledge of the mechanis…

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…

Intracellular compartmentation and plant cell signalling

1997

Compartmentation is an essential feature of eukaryotic cells, and is crucial for the regulation of cell metabolism. Recent progress has significantly improved the understanding of signal transduction pathways in plants, including the activation of light-signalling networks and the tightly controlled generation of the calcium message. Cell compartmentation is important for the regulation and proliferation of these signalling processes.

A secondary mode of action of the herbicide lenacil: Modification of K+ permeability of Acer pseudoplatanus cells

1984

Abstract The action of lenacil on plasmalemma permeability to K+, transmembrane electric potential difference (PD) calculated from the tetraphenylphosphonium distribution, proton extrusion and intracellular pH of Acer pseudoplatanus cells calculated from the 5,5-dimethyloxazolidine,4-dione distribution, was studied and compared with the action of fusicoccin (FC) and diethylstilbestrol (DES). The three compounds temporarily stimulated the rate of 86Rb+ uptake with a half-maximum effect at 5.0 μM for 3-cyclohexyl-6, 7-dihdro-1H-cyclopentapyrimidine-2,4(3H,5H)-dione (lenacil). Lenacil and FC had no action on transmembrane electric potential difference, whereas DES decreased it. Lenacil inhibit…

Variability and cryptic heteromorphism of Ambrosia artemisiifolia seeds: What consequences for its invasion in France

2007

International audience; Background and Aims:Ambrosia artemisiifolia is a ruderal weed introduced from North America to Europe. It produces large amount of achenes which are highly heterogeneous in size. Due to the preponderant role of propagules in invasive plant processes, the achene mass variability related to germination, dispersal strategy and life history traits of offspring were investigated within this species. Methods:The variability in achene mass was quantified among six populations sampled in different habitats. The effects of achene mass variation on germination were studied. The percentages of floating and non-floating achenes were evaluated in the studied populations. The cons…

Control of Erigeron bonariensis with Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus Essential Oils

2020

In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 &micro