Search results for "PTO"
showing 10 items of 28599 documents
Biomechanics and functional morphology of a climbing monocot.
2015
Climbing monocots can develop into large bodied plants despite being confined by primary growth. In our study on Flagellaria indica we measured surprisingly high stem biomechanical properties (in bending and torsion) and we show that the lack of secondary growth is overcome by a combination of tissue maturation processes and attachment mode. This leads to higher densities of mechanically relevant tissues in the periphery of the stem and to the transition from self-supporting to climbing growth. The development of specialised attachment structures has probably underpinned the evolution of numerous other large bodied climbing monocot taxa.
Deficiency in the Phosphorylated Pathway of Serine Biosynthesis Perturbs Sulfur Assimilation.
2018
Although the plant Phosphorylated Pathway of l-Ser Biosynthesis (PPSB) is essential for embryo and pollen development, and for root growth, its metabolic implications have not been fully investigated. A transcriptomics analysis of Arabidopsis (Arabidopsis thaliana) PPSB-deficient mutants at night, when PPSB activity is thought to be more important, suggested interaction with the sulfate assimilation process. Because sulfate assimilation occurs mainly in the light, we also investigated it in PPSB-deficient lines in the day. Key genes in the sulfate starvation response, such as the adenosine 5′phosphosulfate reductase genes, along with sulfate transporters, especially those involved in sulfat…
Comparative transcriptomic analysis of the mechanisms underpinning ageing and fecundity in social insects.
2021
The exceptional longevity of social insect queens despite their lifelong high fecundity remains poorly understood in ageing biology. To gain insights into the mechanisms that might underlie ageing in social insects, we compared gene expression patterns between young and old castes (both queens and workers) across different lineages of social insects (two termite, two bee and two ant species). After global analyses, we paid particular attention to genes of the insulin/insulin-like growth factor 1 signalling (IIS)/target of rapamycin (TOR)/juvenile hormone (JH) network, which is well known to regulate lifespan and the trade-off between reproduction and somatic maintenance in solitary insects…
Effect of methylparaben in Artemia franciscana.
2017
In this study, the toxicity of methylparaben (MeP) an emerging contaminant, was analysed in the sexual species Artemia franciscana, due to its presence in coastal areas and marine saltworks in the Mediterranean region. The acute toxicity (24 h-LC50) of MeP in nauplii was tested and its chronic effect (9 days) evaluated by measuring survival and growth under two sublethal concentrations (0.0085 and 0.017 mg/L). Also, the effect on several key enzymes involved in: antioxidant defences (catalase (CAT) and gluthathion-S-transferase (GST)), neural activity (cholinesterase (ChE)) and xenobiotic biotransformation (carboxylesterase (CbE), was assessed after 48 h under sublethal exposure. The result…
Decline in coccolithophore diversity and impact on coccolith morphogenesis along a natural CO2 gradient
2014
A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation …
Involvement of the glutamate receptor AtGLR3.3 in plant defense signaling and resistance toHyaloperonospora arabidopsidis
2013
Like their animal counterparts, plant glutamate receptor-like (GLR) homologs are intimately associated with Ca(2+) influx through plasma membrane and participate in various physiological processes. In pathogen-associated molecular patterns (PAMP)-/elicitor-mediated resistance, Ca(2+) fluxes are necessary for activating downstream signaling events related to plant defense. In this study, oligogalacturonides (OGs), which are endogenous elicitors derived from cell wall degradation, were used to investigate the role of Arabidopsis GLRs in defense signaling. Pharmacological investigations indicated that GLRs are partly involved in free cytosolic [Ca(2+)] ([Ca(2+)]cyt) variations, nitric oxide (N…
Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies.
2012
This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Eye fluke-induced cataracts in natural fish populations: is there potential for host manipulation?
2010
SUMMARYManipulation of host phenotype (e.g. behaviour, appearance) is suggested to be a common strategy to enhance transmission in trophically transmitted parasites. However, in many systems, evidence of manipulation comes exclusively from laboratory studies and its occurrence in natural host populations is poorly understood. Here, we examined the potential for host manipulation by Diplostomum eye flukes indirectly by quantifying the physiological effects of parasites on fish. Earlier laboratory studies have shown that Diplostomum infection predisposes fish to predation by birds (definitive hosts of the parasites) by reducing fish vision through cataract formation. However, occurrence of ca…
Bioconversion of amino acids into flavouring alcohols and esters by Erwinia carotovora subsp. atroseptica
1991
International audience; Erwinia carotovora subsp. atroseptica produced flavour compounds when infecting endives (Cichorium intybus). These compounds were identified as esters and branched-chain alcohols.They were produced from amino acids and some of them such as methionol, methionol acetate, isobutanol, isobutyl acetate, beta-phenyl ethanol and tryptophol were produced with good yields.
Anhydrobiosis in yeasts: Psychrotolerant yeasts are highly resistant to dehydration.
2018
Yeast cells are able to transition into a state of anhydrobiosis (temporary reversible suspension of metabolism) under conditions of desiccation. One of the most efficient approaches for understanding the mechanisms underlying resistance to dehydration-rehydration is to identify yeasts, which are stable under such treatments, and compare them with moderately resistant species and strains. In the current study, we investigated the resistance to dehydration-rehydration of six psychrotolerant yeast strains belonging to two species. All studied strains of Solicoccozyma terricola and Naganishia albida were found to be highly resistant to dehydration-rehydration. The viability of S. terricola str…