The role of auxin stored in scots pine trunk during spring activation of cambial activity

In a 9-year-old pine girdled during the winter cambial activity was observed below the girdle in the next spring. This indicates that cambial activity was initiated without auxin produced in the spring by buds. The auxin produced in apical shoots successively flows down the stem, where as a result of periodic restriction in transport it remains over the winter till the next year. This auxin of apical origin but locally stored over the winter in the stem is responsible for the activation of cambium before the new flow of auxin produced in the apical meristems arrives. Calculations based on seasonal changes in auxin levels can explain both, earlier spring activation of cambium in the crown and the temporary cambial divisions below the girdle, without assumption of direct auxin synthesis in the lateral meristems.     

Bioweathering of chrysotile by fungi isolated in ophiolitic sites

Asbestos minerals are commonly found in serpentine rocks and because of the hazard to human health, research has recently focused on possible detoxification strategies. Some fungal species that inhabit serpentine sites (two disused chrysotile asbestos mines in the Western Alps) have been isolated and characterized in order to obtain data on their biodiversity and bioweathering abilities on chrysotile fibres. The three dominant species (Verticillium leptobactrum, Paecilomyces lilacinus and Aspergillus fumigatus) have proved to be able to actively remove iron from chrysotile fibres, V. leptobactrum being the most efficient. A wide range of serpentinicolous fungi release siderophores, iron-chelating compounds, that could play a role in iron extraction from fibres. Iron removal had been correlated previously with a decrease in the toxic potential of fibres, and a biotechnological application of fungi can be envisaged for asbestos detoxification.     

Aggressiveness of Fusarium graminearum sensu stricto Isolates in Wheat Kernels in Argentina

This study was designed to investigate the degree of aggressiveness of Fusarium graminearum sensu stricto isolates and its relationship with trichothecene production. In order to characterize Fusarium strains aggressiveness, disease severity was visually assessed as the percentage of spikelets bleached per ear. The severity ranged from a minimum of 27.19% seven days after inoculation to a maximum of 84.73% at the end of the experiment. At maturity the ears were harvested and threshed for grain weight determination. All treatments showed significant differences in kernel weight with respect to the control plants, with a yield reduction of 35–85% in comparison with the yield of the control. Grains infected by F. graminearum may contain significant levels of mycotoxins like trichothecenes. No correlation was found between aggressiveness and the toxins in the kernels at maturity, taking into consideration not only the quantity but also the type of toxin (nivalenol, deoxynivalenol or their acetylderivatives). Kernel weight reduction was a better estimator of the presence of deoxynivalenol in the kernels than the area under the disease progress curve (AUDPC) calculated with severity ratings. The amplified fragment length polymorphism (AFLP) technique was used to establish genetic relationships between 18 Argentinean isolates and eight reference strains of the Fusarium graminearum complex. All the isolates studied grouped with the two F. graminearum s. str. reference isolates, with a similarity coefficient greater than 75%. The other reference strains of the F. graminearum complex were clearly separated, with similarities ranging between 55 and 73%. The AFLP groups had no relationship with toxin accumulation on kernels or with the geographical origin of the isolates. Great heterogeneity was found in the AUDPC, yield reduction and toxin accumulation values across the regions.     

Soluble Receptor for Advanced Glycation End-products regulates age-associated Cardiac Fibrosis

Myocardial aging increases the cardiovascular risk in the elderly. The Receptor for Advanced Glycation End-products (RAGE) is involved in age-related disorders. The soluble isoform (sRAGE) acts as a scavenger blocking the membrane-bound receptor activation. This study aims at investigating RAGE contribution to age-related cardiac remodeling.We analyzed the cardiac function of three different age groups of female Rage-/- and C57BL/6N (WT) mice: 2.5- (Young), 12- (Middle-age, MA) and 21-months (Old) old. While aging, Rage-/- mice displayed an increase in left ventricle (LV) dimensions compared to age-matched WT animals, with the main differences observed in the MA groups. Rage-/- mice showed higher fibrosis and a larger number of α-Smooth Muscle Actin (SMA)+ cells with age, along with increased expression of pro-fibrotic Transforming Growth Factor (TGF)-β1 pathway components. RAGE isoforms were undetectable in LV of WT mice, nevertheless, circulating sRAGE declined with aging and inversely associated with LV diastolic dimensions. Human cardiac fibroblasts stimulated with sRAGE exhibited a reduction in proliferation, pro-fibrotic proteins and TGF-beta Receptor 1 (TGFbR1) expression and Smad2-3 activation. Finally, sRAGE administration to MA WT animals reduced cardiac fibrosis.Hence, our work shows that RAGE associates with age-dependent myocardial changes and indicates sRAGE as an inhibitor of cardiac fibroblasts differentiation and age-dependent cardiac fibrosis.     

The Role of Agonistic Sounds in Male Nest Defence in the Painted Goby Pomatoschistus pictus

Animals often vocalize during territorial challenges as acoustic signals may indicate motivation and fighting ability and contribute to reduce aggressive escalation. Here, we tested the function of agonistic sounds in territorial defence in the painted goby. Pomatoschistus pictus, a small vocal marine fish that defends nests during the breeding season. We first measured the number of times a male approached, avoided, explored, entered and exited two unattended nests associated with either conspecific agonistic sounds or a control: silence or white noise. Acoustic stimuli were played back when the male approached a nest. In a second experimental set, we added visual stimuli, consisting of a conspecific male in a small confinement aquarium near each nest. Even though we found no effect of the visual stimuli, the sound playbacks induced similar effects in both experimental conditions. In the sound vs. silence treatment, we found that when males approached a nest, the playback of conspecific sounds usually triggered avoidance. However, this behaviour did not last as in longer periods males visited nests associated with agonistic sounds more often than silent ones. When the control was white noise, we found no significant effect of the playback treatment in male behaviour. Although we cannot exclude the possibility that other sounds may dissuade nest occupation, our results suggest that agonistic sounds act as territorial intrusion deterrents but are insufficient to prevent nest intrusion on their own. Further studies are needed to test the significance of sound production rate, spectral content and temporal patterns to deter territorial intrusion in fish.     

Chiral Ligand‐Exchange Resolution of Underivatized Amino Acids on a Dynamically Modified Stationary Phase for RP‐HPTLC

The synthesis of Spi(τ‐dec), derived from the selective alkylation of L‐spinacine (4,5,6,7‐tetrahydro‐1H‐imidazo[4,5‐c]pyridine‐6‐carboxylic acid) at the τ‐nitrogen of its heteroaromatic ring, with a linear hydrocarbon chain of 10 carbon atoms, is described here for the first time. Spi(τ‐dec) was successfully employed in the past to prepare home‐made chiral columns for chiral ligand‐exchange high‐performance liquid chromatography. In the present article a new method is described, using Spi(τ‐dec) as a chiral selector in high‐performance thin‐layer chromatography (HPTLC): commercial hydrophobic plates were first coated with Spi(τ‐dec) and then treated with copper sulfate. The performance of this new chiral stationary phase was tested against racemic mixtures of aromatic amino acids, after appropriate optimization of both the conditions of preparation of the plates and the mobile phase composition. The enantioselectivity values obtained for the studied compounds were higher than those reported in the literature for similar systems. The method employed here for the preparation of chiral HPTLC plates proved practical, efficient, and inexpensive. Chirality 26:313–318, 2014. © 2014 Wiley Periodicals, Inc.     

l-Arginine and its metabolites in kidney and cardiovascular disease

l-Arginine is a semi essential amino acid synthesised from glutamine, glutamate and proline via the intestinal-renal axis in humans and most mammals. l-Arginine degradation occurs via multiple pathways initiated by arginase, nitric-oxide synthase, Arg: glycine amidinotransferase, and Arg decarboxylase. These pathways produce nitric oxide, polyamines, proline, glutamate, creatine and agmatine with each having enormous biological importance. Several disease are associated to an l-arginine impaired levels and/or to its metabolites: in particular various l-arginine metabolites may participate in pathogenesis of kidney and cardiovascular disease. l-Arginine and its metabolites may constitute both a marker of pathology progression both the rationale for manipulating l-arginine metabolism as a strategy to ameliorate these disease. A large number of studies have been performed in experimental models of kidney disease with sometimes conflicting results, which underlie the complexity of Arg metabolism and our incomplete knowledge of all the mechanisms involved. Moreover several lines of evidence demonstrate the role of l-arg metabolites in cardiovascular disease and that l-arg administration role in reversing endothelial dysfunction, which is the leading cause of cardiovascular diseases, such as hypertension and atherosclerosis. This review will discuss the implication of the mains l-arginine metabolites and l-arginine-derived guanidine compounds in kidney and cardiovascular disease considering the more recent literature in the field.     

Iron deprivation results in a rapid but not sustained increase of the expression of genes involved in iron metabolism and sulfate uptake in tomato （Solanum lycopersicum L.） seedlings

Characterization of the relationship between sulfur and iron in both Strategy I and Strategy II plants, has proven that low sulfur availability often limits plant capability to cope with iron shortage. Here it was investigated whether the adaptation to iron deficiency in tomato （Solanum lycopersicum L.） plants was associated with an increased root sulfate uptake and translocation capacity, and modified dynamics of total sulfur and thiols accumulation between roots and shoots. Most of the tomato sulfate transporter genes belonging to Groups 1, 2, and 4 were significantly upregulated in iron-deficient roots, as it commonly occurs under S-deficient conditions. The upregulation of the two high affinity sulfate transporter genes, SlST1.1 and SlST1.2, by iron deprivation clearly suggests an increased root capability to take up sulfate. Furthermore, the upregulation of the two low affinity sulfate transporter genes SlST2.1 and SlST4.1 in iron-deficient roots, accompanied by a substantial accumulation of total sulfur and thiols in shoots of＆amp;nbsp;iron-starved plants, likely supports an increased root-to-shoot translocation of sulfate. Results suggest that tomato plants exposed to iron-deficiency are able to change sulfur metabolic balance mimicking sulfur starvation responses to meet the increased demand for methionine and its derivatives, al owing them to cope with this stress.     

Binding of CD157 Protein to Fibronectin Regulates Cell Adhesion and Spreading

CD157/BST-1 behaves both as an ectoenzyme and signaling receptor and is an important regulator of leukocyte trafficking and ovarian cancer progression. However, the molecular interactions underpinning the role of CD157 in these processes remain obscure. The biological functions of CD157 and its partnership with members of the integrin family prompted us to assume the existence of a direct interaction between CD157 and an unknown component of the extracellular matrix. Using solid-phase binding assays and surface plasmon resonance analysis, we demonstrated that CD157 binds fibronectin with high affinity within its heparin-binding domains 1 and 2. Furthermore, we found that CD157 binds to other extracellular matrix proteins containing heparin-binding domains. Finally, we proved that the CD157-fibronectin interaction occurs with living cells, where it elicits CD157-mediated cell responses. Indeed, knockdown of CD157 in Met-5A mesothelial cells changed their morphology and cytoskeleton organization and attenuated the activation of intracellular signaling pathways triggered by fibronectin. This led to impaired cell spreading and adhesion to selected extracellular matrix proteins. Collectively, these findings indicate a central role of CD157 in cell-extracellular matrix interactions and make CD157 an attractive therapeutic target in inflammation and cancer.