ABSTRACT
In recent years, biomonitoring has gained more attention, particularly when assessing the environmental health of significant areas, such as those near waste-to-energy facilities. These requirements coincide with the chance to detect environmental pollutants using sensitive organisms. Bees were shown to be quite effective in evaluating the presence of certain compounds by analyzing their associated matrices, such as pollen, honey, or wax. In our study, we employed the honey bee (Apis mellifera) as an indicator to initially monitor the vicinity of the waste-to-energy plant in Acerra, which is situated in the Campania region of Italy. The primary aim was to determine whether the facility was accountable for any environmental releases of dioxins or dioxin-like compounds. Then, we assessed the presence of additional pollutants in the same area, including trace elements, polycyclic aromatic hydrocarbons, and pesticides, released by human activities. To obtain further information about environmental quality, a second biomonitoring station was installed near the Caivano S.T.I.R. (Waste Shredding, Sifting, and Packaging Plant). The results showed the dioxin levels did not exceed predetermined limitations at the Acerra site, thus demonstrating the efficacy of the waste-to-energy facility and the bees' ability to detect the presence of other pollutants. Additionally, this biomonitoring system exhibited sensitivity to environmental variations, thereby enabling the evaluation of xenobiotic flux between two proximate zones and across temporal scales. This pioneering study suggests the advantages of utilizing bees to detect a wide range of contaminants, thereby providing valuable insights into environmental quality and potential health risks for both ecosystems and human populations.
ABSTRACT
BACKGROUND AND AIMS: Proteases are responsible for protein degradation during leaf senescence, allowing nutrients to be redirected to sink tissues. In a previous work, we reported that sulphur deficiency produced a delay in the leaf senescence of barley (Hordeum vulgare L.) plants, at both vegetative and reproductive stages. In this work, we analyse the effect of sulphur deficiency on the expression of several genes coding for proteases of different catalytic groups, which have been strongly associated with leaf senescence. METHODS: Four independent experiments were performed in order to impose low sulphur availability conditions: one of steady-state sulphur deficiency during the vegetative stage and three of sulphur starvation during vegetative and reproductive stages. KEY RESULTS: Sulphur deficiency inhibited or reduced the senescence-associated induction of seven of the eight proteases analysed. Their induction, as well as senescence and phloem amino acid remobilization, could be achieved with senescence inducers such as methyl-jasmonate (a hormonal stimulus) and darkness, but with different rates of induction dependent on each gene. Sulphur deficiency also exerted an opposite effect on the expression of two cysteine-protease genes (HvSAG12 and HvLEGU) as well as on one serine-protease gene (HvSUBT) according to leaf age and plant phenological stages. All three genes were induced in green leaves but were repressed in senescent leaves of sulphur-deficient plants at the vegetative stage. At the reproductive stage, both cysteine-proteases were only repressed in senescent leaves, while the serine-protease was induced in green and senescent leaves by sulphur deficiency. CONCLUSIONS: Our results highlight the relevance of adequate sulphur nutrition in order to ensure leaf senescence onset and induction of protease genes, which will consequently impact on grain protein composition and quality. In addition, our results provide evidence that leaf age, plant developmental stage and the nature of the stress modulate the sulphur responses.
Subject(s)
Hordeum/genetics , Plant Proteins/genetics , Gene Expression Regulation, Plant , Peptide Hydrolases , Plant Leaves/genetics , SulfurABSTRACT
Proteases play a main role in the mobilization of storage proteins during seed germination. Until today, there is little information about the involvement of serine proteases, particularly subtilases, in the germination of barley grains. The aims of the present work were to study the contribution of serine proteases to the total proteolytic activity induced during germination of barley grains and evaluate the specific involvement of subtilases in this process. Proteolytic activity assayed against azocasein in the presence of specific inhibitors, showed that serine proteases contributed between 10 and 20% of total activity along germination. Subtilase activity increased from day 1 after imbibition with a peak between days 4-5. Moreover, in vivo determination of subtilase activity in germinating grains revealed increasing activity along germination mainly localized in the seed endosperm and developing rootlets. Finally, the expression of 19 barley genes encoding subtilases was measured by real time PCR during germination. Three of the analyzed genes increased their expression along germination, five showed a transient induction, one was down-regulated, nine remained unchanged and one was not expressed. The present work demonstrates the involvement of subtilases in germination of barley grains and describes the positive association of eight subtilase genes to this process.
Subject(s)
Germination , Hordeum/growth & development , Plant Proteins/metabolism , Seedlings/growth & development , Subtilisins/metabolism , Amino Acids/metabolism , Gene Expression Regulation, Plant , Hordeum/enzymology , Hordeum/metabolism , Proteolysis , Real-Time Polymerase Chain Reaction , Seedlings/enzymology , Seedlings/metabolismABSTRACT
Subtilases are one of the largest groups of the serine protease family and are involved in many aspects of plant development including senescence. In wheat, previous reports demonstrate an active participation of two senescence-induced subtilases, denominated P1 and P2, in nitrogen remobilization during whole plant senescence. The aim of the present study was to examine the participation of subtilases in senescence-associated proteolysis of barley leaves while comparing different senescence types. With this purpose, subtilase enzymatic activity, immunodetection with a heterologous antiserum and gene expression of 11 subtilase sequences identified in barley databases by homology to P1 were analyzed in barley leaves undergoing dark-induced or natural senescence at the vegetative or reproductive growth phase. Results showed that subtilase specific activity as well as two inmunoreactive bands representing putative subtilases increased in barley leaves submitted to natural and dark-induced senescence. Gene expression analysis showed that two of the eleven subtilase genes analyzed, HvSBT3 and HvSBT6, were up-regulated in all the senescence conditions tested while HvSBT2 was expressed and up-regulated only during dark-induced senescence. On the other hand, HvSBT1, HvSBT4 and HvSBT7 were down-regulated during senescence and two other subtilase genes (HvSBT10 and HvSBT11) showed no significant changes. The remaining subtilase genes were not detected. Results demonstrate an active participation of subtilases in protein degradation during dark-induced and natural leaf senescence of barley plants both at the vegetative and reproductive stage, and, based on their expression profile, postulate HvSBT3 and HvSBT6 as key components of senescence-associated proteolysis.
Subject(s)
Gene Expression Regulation, Plant , Genes, Plant , Hordeum/enzymology , Hordeum/growth & development , Plant Proteins/genetics , Subtilisins/genetics , Amino Acid Sequence , Chlorophyll/metabolism , Darkness , Databases, Genetic , Gene Expression Regulation, Developmental , Hordeum/genetics , Plant Leaves/enzymology , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Proteins/chemistry , Plant Proteins/metabolism , Real-Time Polymerase Chain Reaction , Reproduction/genetics , Ribulose-Bisphosphate Carboxylase/metabolism , Sequence Alignment , Subtilisins/chemistry , Subtilisins/metabolismABSTRACT
OBJECTIVES: The purpose of this study was to compare conventional 2-dimensional (2D) B-mode sonography with 3-dimensional (3D) sonography for assessing gallbladder volume and contractility. METHODS: Gallbladder volume and contractility were evaluated in 32 healthy volunteers after fasting and abstinence from smoking for 8 hours and after a standardized balanced liquid meal. The gallbladder was evaluated with 2D sonography (with the use of the ellipsoid method) and with 3D sonography using a volumetric matrix probe. Both measurements were made by an operator who was skilled in sonography and an unskilled operator. The group of volunteers was subdivided into 2 subgroups including 16 participants, which represented the "2 moments" of acquisition by the techniques, particularly for the unskilled operator. RESULTS: The postprandial volumes obtained with 3D sonography were significantly lower in comparison to the volumes obtained with 2D sonography (P= .013), and there was a significant difference between the measurements made by the skilled and unskilled operators only for 2D sonography (P< .001), whereas between the 2 moments of acquisition by the 3D technique, there was no significant difference. The reproducibility of the technique for evaluation of gallbladder volumes was higher for 3D sonography than 2D sonography, particularly for the postprandial evaluation. CONCLUSIONS: The new 3D sonographic method using a volumetric matrix probe is a simple, reliable, and more reproducible technique than conventional 2D sonography, even if performed by an unskilled operator, and it allows a reliable stimulation test for a gallbladder dynamic study.
Subject(s)
Gallbladder/diagnostic imaging , Gallbladder/physiology , Imaging, Three-Dimensional/methods , Adult , Female , Gallbladder/anatomy & histology , Humans , Male , Organ Size , Prospective Studies , Reproducibility of ResultsABSTRACT
An essential goal for modern agriculture is the simultaneous improvement of productivity efficiency and nutrient use efficiency. One way to achieve this goal in crops is to enhance nitrogen (N) and phosphorus (P) acquisition through the mycorrhizal association. This study examined the effect of mycorrhization on post-anthesis N and P dynamics and its impact on grain yield and quality in barley. In addition, the efficiency of both N and P utilization and remobilization was evaluated. With those purposes, barley plants inoculated or not with Rhizophagus intraradices were grown in a soil poor in N and P under greenhouse conditions. Inoculation with R. intraradices in barley enhanced both N and P content in grain and vegetative tissue and reduced phloem amino acid export rate. On the other hand, both N and P vegetative tissue content and phloem amino acid and P export rates decreased during grain filling, whereas N and P grain content increased in both treatments according to the senescence process. However, whereas N grain concentration decreased during grain filling, P grain concentration did not vary, thus suggesting a differential regulation on grain filling. Inoculation with R. intraradices improved the yield and grain quality, thus demonstrating that inoculation with R. intraradices in barley is beneficial, but mycorrhization caused a diminution in nutrient utilization efficiency. As the phloem remobilization rate of amino acids and P did not decrease during grain filling in R. intraradices-inoculated plants compared to non-inoculated ones, these results suggest that nutrient utilization efficiency is most probably regulated by sink strength rather by a mycorrhizal effect.
Subject(s)
Agricultural Inoculants/growth & development , Glomeromycota/growth & development , Hordeum/metabolism , Hordeum/microbiology , Mycorrhizae/growth & development , Nitrogen/metabolism , Phosphorus/metabolism , Agricultural Inoculants/metabolism , Glomeromycota/metabolism , Hordeum/chemistry , Hordeum/growth & development , Mycorrhizae/metabolism , Plant Roots/growth & development , Plant Roots/metabolism , Plant Roots/microbiology , Seeds/chemistry , Seeds/growth & development , Seeds/metabolism , Seeds/microbiology , Soil MicrobiologyABSTRACT
Senescence is the final developmental stage of every plant organ, which leads to cell death. It is a highly regulated process, involving differential gene expression and outstanding increment in the rate of protein degradation. Senescence-associated proteolysis enables the remobilization of nutrients, such as nitrogen (N), from senescent tissues to developing organs or seeds. In addition to the nutrient recycling function, senescence-associated proteases are also involved in the regulation of the senescence process. Nearly, all protease families have been associated with some aspects of plant senescence, and numerous reports addressing the new identification of senescence-associated proteases are published every year. Here, we provide an updated report with the most recent information published in the field, focusing on senescence-associated proteases presumably involved in N remobilization.
Subject(s)
Nitrogen/metabolism , Peptide Hydrolases/metabolism , Plant Proteins/metabolism , Plants/enzymology , Cell Death , Chloroplast Proteins/metabolism , Chloroplasts/enzymology , Enzyme Activation , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Genes, Plant , Peptide Hydrolases/genetics , Plant Development , Plant Leaves/enzymology , Plant Leaves/genetics , Plant Proteins/genetics , Plants/genetics , Proteasome Endopeptidase Complex/metabolism , Proteolysis , Stress, Physiological , Substrate SpecificityABSTRACT
Celiac disease is an autoimmune disorder primarily targeting the small bowel, although extraintestinal extensions have been reported. The autoimmune processes can affect the liver with manifestations such as primary biliary cirrhosis and autoimmune hepatitis. We describe a 61-year-old woman with celiac disease and an increased levels of aminotransferases. The persistence of increased levels of aminotransferases after 1 year of gluten-free diet and the positivity for an anti-nuclear and anti-double-strand DNA antibodies led to a misdiagnosis of systemic lupus erythematosus-related hepatitis. Based on these findings the patient was placed on steroids, which after a few months were stopped because of the onset of diabetes mellitus. Soon after steroid withdrawal, the patient had a marked increase in aminotransferases and γ-globulins, and a liver biopsy revealed chronic active hepatitis. A course of three months of steroids and azathioprine normalized both biochemical and clinical parameters. Currently the patient is symptom-free and doing well. In conclusion, a hypertransaminasemia persisting after a gluten-free diet should be interpreted as a sign of coexisting autoimmune liver disease. Any autoantibody positivity (in this case to ANA and anti-dsDNA) should be carefully considered in order to avoid misdiagnosis delaying appropriate clinical management.
ABSTRACT
Nitrogen (N) remobilization in wheat (Triticum aestivum) plants is crucial because it determines the grain protein concentration and the baking quality of flour. In order to evaluate the influence of cytokinins on N remobilization during N starvation, we analyzed various N remobilization parameters in wheat plants that were watered with 6-benzylaminopurine (BAP) either with or without KNO(3). Besides, the effects of BAP on protein synthesis were evaluated, and the size and ultrastructure of chloroplasts of BAP-treated plants were studied. BAP supply inhibited N remobilization of plants independently of N supply as shown by the increase in protein, Rubisco, chlorophyll, sugar and starch concentrations in the older leaves, the decrease in amino acid and sugar export to the phloem, and the decrease in protein, Rubisco and chlorophyll concentrations in the younger leaves. Besides, BAP supply increased nitrate reductase activity and decreased nitrate concentration, thus suggesting an increased assimilatory capacity. The increase in protein concentration could be explained mainly by a significant decrease in protein degradation and, to a lesser extent, by an increase in protein synthesis. Finally, an increase both in the size of the chloroplast and in the plastoglobuli and starch contents in BAP-supplied plants was observed. We propose that cytokinins retain the sink activity of the older leaves by inhibiting amino acid and sugar export to the phloem and stimulating assimilate accumulation in the chloroplasts of the older leaves. Besides, BAP may increase protein concentration of the older leaves both by decreasing protein degradation and maintaining protein synthesis even under stress conditions.
Subject(s)
Chloroplasts/ultrastructure , Cytokinins/physiology , Nitrogen/metabolism , Triticum/metabolism , Base Sequence , DNA Primers , Microscopy, Electron , Polymerase Chain Reaction , Triticum/growth & development , Triticum/ultrastructureABSTRACT
The possible regulation of amino acid remobilization via the phloem in wheat (Triticum aestivum L.) by the primary enzyme in nitrogen (N) assimilation and re-assimilation, glutamine synthetase (GS, E.C. 6.3.1.2) was studied using two conditions known to alter N phloem transport, N deficiency and cytokinins. The plants were grown for 15 days in controlled conditions with optimum N supply and then N was depleted from and/or 6-benzylaminopurine was added to the nutrient solution. Both treatments generated an induction of GS1, monitored at the level of gene expression, protein accumulation and enzyme activity, and a decrease in the exudation of amino acids to the phloem, obtained with EDTA technique, which correlated negatively. GS inhibition by metionine sulfoximide (MSX) produced an increase of amino acids exudation and the inhibitor successfully reversed the effect of N deficiency and cytokinin addition over phloem exudation. Our results point to an important physiological role for GS1 in the modulation of amino acids export levels in wheat plants.
Subject(s)
Amino Acids/metabolism , Glutamate-Ammonia Ligase/genetics , Phloem/metabolism , Plant Proteins/genetics , Triticum/genetics , Benzyl Compounds , Biological Transport/drug effects , Electrophoresis, Polyacrylamide Gel , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Plant/drug effects , Glutamate-Ammonia Ligase/classification , Glutamate-Ammonia Ligase/metabolism , Isoenzymes/classification , Isoenzymes/genetics , Isoenzymes/metabolism , Kinetin/pharmacology , Methionine Sulfoximine/pharmacology , Nitrates/pharmacology , Phylogeny , Plant Proteins/metabolism , Purines , Reverse Transcriptase Polymerase Chain Reaction , Triticum/enzymology , Triticum/metabolismABSTRACT
Chronic intestinal pseudo-obstruction (CIPO) is a severe digestive syndrome characterized by derangement of gut propulsive motility which resembles mechanical obstruction, in the absence of any obstructive process. Although uncommon in clinical practice, this syndrome represents one of the main causes of intestinal failure and is characterized by high morbidity and mortality. It may be idiopathic or secondary to a variety of diseases. Most cases are sporadic, even though familial forms with either dominant or recessive autosomal inheritance have been described. Based on histological features intestinal pseudo-obstruction can be classified into three main categories: neuropathies, mesenchymopathies, and myopathies, according on the predominant involvement of enteric neurones, interstitial cells of Cajal or smooth muscle cells, respectively. Treatment of intestinal pseudo-obstruction involves nutritional, pharmacological and surgical therapies, but it is often unsatisfactory and the long-term outcome is generally poor in the majority of cases.
Subject(s)
Intestinal Pseudo-Obstruction , Chronic Disease , Digestive System Surgical Procedures , Disease Progression , Enteric Nervous System/physiopathology , Gastrointestinal Agents/therapeutic use , Gastrointestinal Motility , Humans , Intestinal Pseudo-Obstruction/diagnosis , Intestinal Pseudo-Obstruction/etiology , Intestinal Pseudo-Obstruction/physiopathology , Intestinal Pseudo-Obstruction/therapy , Intestines/innervation , Muscle, Smooth/innervation , Nutritional Support , Treatment OutcomeABSTRACT
Solar ultraviolet-B radiation (UV-B) can have large impacts on the interactions between plants and herbivorous insects. Several studies have documented effects of UV-B-induced changes in plant tissue quality on the feeding performance of insect larvae. In contrast, the effects of UV-B-induced plant responses on the behavior of adult insects have received little attention. We carried out a series of field and glasshouse experiments using the model plant Arabidopsis thaliana L. and the crucifer-specialist insect Plutella xylostella L. (diamondback moth) to investigate the effects of UV-B on natural herbivory and plant-insect interactions. Natural herbivory under field conditions was less severe on plants exposed to ambient UV-B than on plants grown under filters that attenuated the UV-B component of solar radiation. This reduced herbivory could not be accounted for by effects of UV-B on larval feeding preference and performance, as P. xylostella caterpillars did not respond to changes in plant quality induced by UV-B. In contrast, at the adult stage, the insects presented clear behavioral responses: P. xylostella moths deposited significantly more eggs on plants grown under attenuated UV-B levels than on plants exposed to ambient UV-B. The deterring effect of UV-B exposure on insect oviposition was absent in jar1-1, a mutant with impaired jasmonic acid (JA) sensitivity, but it was conserved in mutants with altered ethylene signaling. The jar1-1 mutant also presented reduced levels of UV-absorbing phenolic compounds than the other genotypes that we tested. Our results suggest that variations in UV-B exposure under natural conditions can have significant effects on insect herbivory by altering plant traits that female adults use as sources of information during the process of host selection for oviposition. These effects of natural UV-B on plant quality appear to be mediated by activation of signaling circuits in which the defense-related hormone JA plays a functional role.