Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 44
Filter
1.
Front Psychol ; 15: 1348965, 2024.
Article in English | MEDLINE | ID: mdl-38784627

ABSTRACT

Introduction: The quiet ego indicates a more compassionate conception of self-identity that integrates others into the self by lowering the intensity of the ego and enhancing the awareness of the present moment. The Quiet Ego Scale (QES) is a 14-item self-report measure of quiet ego, and it is composed of the following four psychological domains: detached awareness, inclusive identity, perspective taking, and growth. The present study aimed to test the psychometric properties of the Quiet Ego Scale within the Italian cultural context (iQES). Methods: A total of 160 Italian university students aged between 20 and 42 years, with a mean age of 22.85 years (SD = 3.41), completed the measures of the iQES and of other psychological dimensions. The psychometrics properties of iQES were assessed based on its internal consistency, test-retest reliability, and construct validity through comparisons with other correlated psychological measures. Results: Analyses confirmed the psychometrics properties of iQES. As in previous studies, the quiet ego was positively associated with the indicators of resilience (p < 0.01), happiness (p < 0.05), self-esteem (p < 0.01), and psychological wellbeing (p < 0.01). Discussion: The study discussed the possible uses of the iQES in the field of mental health, specifically focusing on improving adherence to psychological therapies and enhancing psychological and social well-being. The results indicated strong psychometric properties of the iQES in measuring the quiet ego construct. Our findings enrich the literature on the validity of the iQES and highlight the multidimensional nature of the quiet ego construct.

2.
Plants (Basel) ; 12(23)2023 Nov 29.
Article in English | MEDLINE | ID: mdl-38068650

ABSTRACT

Plant physiological status is the interaction between the plant genome and the prevailing growth conditions. Accurate characterization of plant physiology is, therefore, fundamental to effective plant phenotyping studies; particularly those focused on identifying traits associated with improved yield, lower input requirements, and climate resilience. Here, we outline the approaches used to assess plant physiology and how these techniques of direct empirical observations of processes such as photosynthetic CO2 assimilation, stomatal conductance, photosystem II electron transport, or the effectiveness of protective energy dissipation mechanisms are unsuited to high-throughput phenotyping applications. Novel optical sensors, remote/proximal sensing (multi- and hyperspectral reflectance, infrared thermography, sun-induced fluorescence), LiDAR, and automated analyses of below-ground development offer the possibility to infer plant physiological status and growth. However, there are limitations to such 'indirect' approaches to gauging plant physiology. These methodologies that are appropriate for the rapid high temporal screening of a number of crop varieties over a wide spatial scale do still require 'calibration' or 'validation' with direct empirical measurement of plant physiological status. The use of deep-learning and artificial intelligence approaches may enable the effective synthesis of large multivariate datasets to more accurately quantify physiological characters rapidly in high numbers of replicate plants. Advances in automated data collection and subsequent data processing represent an opportunity for plant phenotyping efforts to fully integrate fundamental physiological data into vital efforts to ensure food and agro-economic sustainability.

3.
BMC Surg ; 23(1): 311, 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37833715

ABSTRACT

INTRODUCTION: The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (SIUCP: Società Italiana Unitaria di Colon-Proctologia) on the diagnosis and management of anal fissure, with the purpose to guide every physician in the choice of the best treatment option, according with the available literature. METHODS: A panel of experts was designed and charged by the Board of the SIUCP to develop key-questions on the main topics covering the management of anal fissure and to performe an accurate search on each topic in different databanks, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in different rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to the PICO criteria, and the statements developed adopting the GRADE methodology. CONCLUSIONS: In patients with acute anal fissure the medical therapy with dietary and behavioral norms is indicated. In the chronic phase of disease, the conservative treatment with topical 0.3% nifedipine plus 1.5% lidocaine or nitrates may represent the first-line therapy, eventually associated with ointments with film-forming, anti-inflammatory and healing properties such as Propionibacterium extract gel. In case of first-line treatment failure, the surgical strategy (internal sphincterotomy or fissurectomy with flap), may be guided by the clinical findings, eventually supported by endoanal ultrasound and anal manometry.


Subject(s)
Colorectal Surgery , Fissure in Ano , Humans , Fissure in Ano/diagnosis , Fissure in Ano/surgery , Lidocaine/therapeutic use , Colon , Chronic Disease , Anal Canal/surgery , Treatment Outcome
4.
J Dairy Sci ; 106(12): 8375-8388, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37678781

ABSTRACT

The present study aims to characterize the artisanal saffron ricotta cheese produced from the whey of Piacentinu Ennese protected designation of origin (PDO) cheesemaking, including via technological parameters detected during the production process and by assessment of the main physicochemical, microbial, sensory, and antioxidant characteristics. A survey on the manufacture process of saffron and control ricotta cheese was conducted on 3 farms, located in the production area of the Piacentinu Ennese PDO cheese. pH and temperature followed a specific behavior, characterized by an inverse trend where pH decreased and temperature increased, playing an important role in the production process. All the analytical parameters were affected by the presence of saffron, also showing high between-farm variability, with significantly higher total solids and fat contents in saffron ricotta cheese compared with the control cheese (28.68% vs. 23.86%, and 19.83% vs. 14.22%, respectively). Microbial analysis showed significantly lower values in saffron compared with control ricotta cheese, for coliforms (1.51 vs. 1.91 log10 cfu/g, respectively), yeasts (1.55 vs. 2.06 log10 cfu/g, respectively), and molds (1.03 vs. 1.30 log10 cfu/g, respectively), denoting potential reduction of microbial growth asserted by saffron. Escherichia coli concentration (1.26 log10 cfu/g) in saffron ricotta cheese was in accordance with EU Regulation 2073/2005 and then safe for consumption. The presence of saffron influenced all sensory attributes, particularly color and aroma. Interestingly, high total antioxidant activity was found in saffron ricotta cheese (372 µC) compared with the control cheese. Thus, this artisanal dairy production could be considered a suitable option for functional foods with antimicrobial properties, due to the presence of saffron, which may contribute to extend the shelf life of the product. Further studies need to focus on the bioactive compounds that affect the antioxidant proprieties, characterization of the microbiota of saffron ricotta cheese, and evaluation of consumers' acceptance and perception as well as market demand.


Subject(s)
Cheese , Crocus , Animals , Cheese/analysis , Milk/chemistry , Antioxidants/analysis , Sicily
5.
Environ Microbiol Rep ; 15(6): 459-483, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37226644

ABSTRACT

Legumes maintain soil fertility thanks to their associated microbiota but are threatened by climate change that causes soil microbial community structural and functional modifications. The core microbiome associated with different chickpea and lentil genotypes was described after an unexpected climatic event. Results showed that chickpea and lentil bulk soil microbiomes varied significantly between two sampling time points, the first immediately after the rainfall and the second 2 weeks later. Rhizobia were associated with the soil of the more productive chickpea genotypes in terms of flower and fruit number. The root-associated bacteria and fungi were surveyed in lentil genotypes, considering that several parcels showed disease symptoms. The metabarcoding analysis revealed that reads related to fungal pathogens were significantly associated with one lentil genotype. A lentil core prokaryotic community common to all genotypes was identified as well as a genotype-specific one. A higher number of specific bacterial taxa and an enhanced tolerance to fungal diseases characterized a lentil landrace compared to the commercial varieties. This outcome supported the hypothesis that locally adapted landraces might have a high recruiting efficiency of beneficial soil microbes.


Subject(s)
Cicer , Lens Plant , Microbiota , Soil , Microbiota/genetics , Bacteria/genetics , Genotype , Soil Microbiology , Plant Roots/microbiology
6.
Int J Mol Sci ; 24(4)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36835502

ABSTRACT

Distinct photosynthetic physiologies are found within the Moricandia genus, both C3-type and C2-type representatives being known. As C2-physiology is an adaptation to drier environments, a study of physiology, biochemistry and transcriptomics was conducted to investigate whether plants with C2-physiology are more tolerant of low water availability and recover better from drought. Our data on Moricandia moricandioides (Mmo, C3), M. arvensis (Mav, C2) and M. suffruticosa (Msu, C2) show that C3 and C2-type Moricandias are metabolically distinct under all conditions tested (well-watered, severe drought, early drought recovery). Photosynthetic activity was found to be largely dependent upon the stomatal opening. The C2-type M. arvensis was able to secure 25-50% of photosynthesis under severe drought as compared to the C3-type M. moricandioides. Nevertheless, the C2-physiology does not seem to play a central role in M. arvensis drought responses and drought recovery. Instead, our biochemical data indicated metabolic differences in carbon and redox-related metabolism under the examined conditions. The cell wall dynamics and glucosinolate metabolism regulations were found to be major discriminators between M. arvensis and M. moricandioides at the transcription level.


Subject(s)
Brassicaceae , Droughts , Drought Resistance , Brassicaceae/metabolism , Photosynthesis/physiology , Plants/metabolism , Water/metabolism , Plant Leaves/metabolism
7.
Sci Total Environ ; 863: 160908, 2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36535478

ABSTRACT

The limits for stomatal conductance are set by stomatal size (SS) and density (SD). An inverse relationship between SS and SD has been observed in fossil and living plants. This has led to hypotheses proposing that the ratio of SS to SD influences the diffusion pathway for CO2 and degree of physiological stomatal control. However, conclusive evidence supportive of a functional role of the SS-SD relationship is not evident, and patterns in SS-SD may simply reflect geometric constraints in stomatal spacing over a leaf surface. We examine published and new data to investigate the potential functional significance of the relationship between SS and SD to atmospheric [CO2] in multiple generation adaptive responses and short-term acclamatory adjustment of stomatal morphology. Consistent patterns in SS and SD were not evident in fossil and living plants adapted to high [CO2] over many generations. However, evolutionary adaptation to [CO2] strongly affected SS and SD responses to elevated [CO2], with plants adapted to the 'low' [CO2] of the past 10 million years (Myr) showing adjustment of SS-SD, while members of the same species adapted to 'high' [CO2] showed no response. This may suggest that SS and SD responses to future [CO2] will likely constrain the stimulatory effect of 'CO2-fertilisation' on photosynthesis. Angiosperms generally possessed higher densities of smaller stomata that corresponded to a greater degree of physiological stomatal control consistent with selective pressures induced by declining [CO2] over the past 90 Myr. Atmospheric [CO2] has likely shaped stomatal size and density relationships alongside the interaction with stomatal physiological behaviour. The rate and predicted extent of future increases in [CO2] will have profound impacts on the selective pressures shaping SS and SD. Understanding the trade-offs involved in SS-SD and the interaction with [CO2], will be central to the development of more productive climate resilient crops.


Subject(s)
Carbon Dioxide , Plant Stomata , Plant Stomata/physiology , Carbon Dioxide/metabolism , Plant Leaves/physiology , Photosynthesis/physiology , Climate
8.
Sci Total Environ ; 840: 156606, 2022 Sep 20.
Article in English | MEDLINE | ID: mdl-35691351

ABSTRACT

The atmospheric concentration of carbon dioxide ([CO2]) and oxygen ([O2]) directly influence rates of photosynthesis (PN) and photorespiration (RPR) through the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Levels of [CO2] and [O2] have varied over Earth history affecting rates of both CO2 uptake and loss, alongside associated transpirative water-loss. The availability of CO2 has likely acted as a stronger selective pressure than [O2] due to the greater specificity of RubisCO for CO2. The role of [O2], and the interaction of [O2] and [CO2], in plant evolutionary history is less understood. We exposed twelve phylogenetically diverse species to combinations of sub-ambient, ambient and super-ambient [O2] and [CO2] to examine the biochemical and diffusive components of PN and the possible role of [O2] as a selective pressure. Photosynthesis, photosynthetic capacity and stomatal, mesophyll and total conductance to CO2 were higher in the derived eudicot and monocot angiosperms than the more basal ferns, gymnosperms and basal angiosperms which originated in atmospheres characterised by higher CO2:O2 ratios. The ratio of RPR:PN was lower in the monocots, consistent with greater carboxylation capacity and higher stomatal and mesophyll conductance making easier CO2 delivery to chloroplasts. The effect of [O2] and [CO2] on PN/RPR was less evident in more derived species with a higher conductance to CO2. The effect of [O2] was less apparent at high [CO2], suggesting that atmospheric [O2] may only have exerted a strong selective pressure on plant photosynthetic processes during periods characterised by low atmospheric CO2:O2 ratios. Current rising [CO2] will predominantly enhance PN rates in species with low diffusive conductance to CO2.


Subject(s)
Carbon Dioxide , Ribulose-Bisphosphate Carboxylase , Atmosphere , Oxygen , Photosynthesis , Plant Leaves/metabolism , Plants/metabolism , Ribulose-Bisphosphate Carboxylase/metabolism
9.
Plants (Basel) ; 10(9)2021 Sep 02.
Article in English | MEDLINE | ID: mdl-34579359

ABSTRACT

Irrigation is fundamental for agriculture but, as climate change becomes more persistent, there is a need to conserve water and use it more efficiently. It is therefore crucial to identify cultivars that can tolerate drought. For economically relevant crops, such as tomatoes, this purpose takes on an even more incisive role and local agrobiodiversity is a large genetic reservoir of promising cultivars. In this study, nine local Italian cultivars of tomatoes plus four widely used commercial cultivars were considered. These experienced about 20 d of drought, either at vegetative or reproductive phase. Various physio-morphological parameters were monitored, such as stomatal conductance (gs), photosynthesis (A), water use efficiency (WUE), growth (GI) and soil water content (SWC). The different responses and behaviors allowed to divide the cultivars into three groups: tolerant, susceptible, and intermediate. The classification was also confirmed by a principal component analysis (PCA). The study, in addition to deepening the knowledge of local Italian tomato cultivars, reveals how some cultivars perform better under stress condition than commercial ones. Moreover, the different behavior depends on the genotype and on the growth phase of plants. In fact, the Perina cultivar is the most tolerant during vegetative growth while the Quarantino cultivar is mostly tolerant at reproductive stage. The results suggest that selection of cultivars could lead to a more sustainable agriculture and less wasteful irrigation plans.

10.
Int J Mol Sci ; 22(15)2021 Aug 02.
Article in English | MEDLINE | ID: mdl-34361067

ABSTRACT

Carotenoids and phenylpropanoids play a dual role of limiting and countering photooxidative stress. We hypothesize that their "antioxidant" function is prominent in plants exposed to summer drought, when climatic conditions exacerbate the light stress. To test this, we conducted a field study on Phillyrea latifolia, a Mediterranean evergreen shrub, carrying out daily physiological and biochemical analyses in spring and summer. We also investigated the functional role of the major phenylpropanoids in different leaf tissues. Summer leaves underwent the most severe drought stress concomitantly with a reduction in radiation use efficiency upon being exposed to intense photooxidative stress, particularly during the central hours of the day. In parallel, a significant daily variation in both carotenoids and phenylpropanoids was observed. Our data suggest that the morning-to-midday increase in zeaxanthin derived from the hydroxylation of ß-carotene to sustain non-photochemical quenching and limit lipid peroxidation in thylakoid membranes. We observed substantial spring-to-summer and morning-to-midday increases in quercetin and luteolin derivatives, mostly in the leaf mesophyll. These findings highlight their importance as antioxidants, countering the drought-induced photooxidative stress. We concluded that seasonal and daily changes in photosynthetic and non-photosynthetic pigments may allow P. latifolia leaves to avoid irreversible photodamage and to cope successfully with the Mediterranean harsh climate.


Subject(s)
Antioxidants/pharmacology , Oleaceae/drug effects , Phenylpropionates/pharmacology , Plant Leaves/drug effects , Radiation-Protective Agents/pharmacology , Seasons , Stress, Physiological , Carotenoids/pharmacology , Droughts , Light , Lipid Peroxidation , Oleaceae/growth & development , Oleaceae/radiation effects , Oxidative Stress , Photosynthesis , Pigmentation , Plant Leaves/growth & development , Plant Leaves/radiation effects
11.
Oecologia ; 197(4): 867-883, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33515295

ABSTRACT

Stomata are central players in the hydrological and carbon cycles, regulating the uptake of carbon dioxide (CO2) for photosynthesis and transpirative loss of water (H2O) between plants and the atmosphere. The necessity to balance water-loss and CO2-uptake has played a key role in the evolution of plants, and is increasingly important in a hotter and drier world. The conductance of CO2 and water vapour across the leaf surface is determined by epidermal and stomatal morphology (the number, size, and spacing of stomatal pores) and stomatal physiology (the regulation of stomatal pore aperture in response to environmental conditions). The proportion of the epidermis allocated to stomata and the evolution of amphistomaty are linked to the physiological function of stomata. Moreover, the relationship between stomatal density and [CO2] is mediated by physiological stomatal behaviour; species with less responsive stomata to light and [CO2] are most likely to adjust stomatal initiation. These differences in the sensitivity of the stomatal density-[CO2] relationship between species influence the efficacy of the 'stomatal method' that is widely used to infer the palaeo-atmospheric [CO2] in which fossil leaves developed. Many studies have investigated stomatal physiology or morphology in isolation, which may result in the loss of the 'overall picture' as these traits operate in a coordinated manner to produce distinct mechanisms for stomatal control. Consideration of the interaction between stomatal morphology and physiology is critical to our understanding of plant evolutionary history, plant responses to on-going climate change and the production of more efficient and climate-resilient food and bio-fuel crops.


Subject(s)
Photosynthesis , Plant Stomata , Atmosphere , Carbon Dioxide , Plant Leaves
12.
Ann Am Thorac Soc ; 18(6): 1020-1026, 2021 06.
Article in English | MEDLINE | ID: mdl-33395553

ABSTRACT

Rationale: Treatment with noninvasive ventilation (NIV) in coronavirus disease (COVID-19) is frequent. Shortage of intensive care unit (ICU) beds led clinicians to deliver NIV also outside ICUs. Data about the use of NIV in COVID-19 is limited.Objectives: To describe the prevalence and clinical characteristics of patients with COVID-19 treated with NIV outside the ICUs. To investigate the factors associated with NIV failure (need for intubation or death).Methods: In this prospective, single-day observational study, we enrolled adult patients with COVID-19 who were treated with NIV outside the ICU from 31 hospitals in Lombardy, Italy.Results: We collected data on demographic and clinical characteristics, ventilatory management, and patient outcomes. Of 8,753 patients with COVID-19 present in the hospitals on the study day, 909 (10%) were receiving NIV outside the ICU. A majority of patients (778/909; 85%) patients were treated with continuous positive airway pressure (CPAP), which was delivered by helmet in 617 (68%) patients. NIV failed in 300 patients (37.6%), whereas 498 (62.4%) patients were discharged alive without intubation. Overall mortality was 25%. NIV failure occurred in 152/284 (53%) patients with an arterial oxygen pressure (PaO2)/fraction of inspired oxygen (FiO2) ratio <150 mm Hg. Higher C-reactive protein and lower PaO2/FiO2 and platelet counts were independently associated with increased risk of NIV failure.Conclusions: The use of NIV outside the ICUs was common in COVID-19, with a predominant use of helmet CPAP, with a rate of success >60% and close to 75% in full-treatment patients. C-reactive protein, PaO2/FiO2, and platelet counts were independently associated with increased risk of NIV failure.Clinical trial registered with ClinicalTrials.gov (NCT04382235).


Subject(s)
COVID-19/therapy , Continuous Positive Airway Pressure/methods , Hospital Mortality , Hypoxia/therapy , Intubation, Intratracheal/statistics & numerical data , Noninvasive Ventilation/methods , Patients' Rooms , Respiratory Insufficiency/therapy , Aged , Cannula , Female , Humans , Intensive Care Units , Italy , Male , Middle Aged , Oxygen Inhalation Therapy , Prospective Studies , SARS-CoV-2 , Treatment Failure
13.
Riv Psichiatr ; 55(4): 222-226, 2020.
Article in Italian | MEDLINE | ID: mdl-32724234

ABSTRACT

AIM: This paper aims to study, evaluate and compare the effectiveness of two group interventions within a Psychiatric Intensive Care Unit (PICU). The outcome indicators of the satisfaction of patients and their families with the ward were evaluated with a Satisfaction Questionnaire on the department, and their satisfaction with the groups were evaluated with the Satisfaction Questionnaire for the groups. The two theoretical orientations examined are the cognitive-behavioural therapy, with group cognitive-behavioural intervention in the context of SPDC, and psychoanalysis, with multifamily psychoanalysis groups, according to the model of Jorge García Badaracco. METHODS: The sample is composed of 83 users (42 males and 41 females) participating in the groups; 41 users (23 males and 18 females) not participating in the groups; 54 family members participating in the groups; 41 family members not participating in the groups. RESULTS: The results show an improvement of satisfaction with activities compared to the hospitalisation into the ward (p<.01), an improvement in the perception of the ward climate (p<.01) of the users participating in the groups, regardless of the orientation of reference, but it shows a greater effectiveness of groups with cognitive-behavioral group orientation (p<.001). DISCUSSION AND CONCLUSIONS: The results indicate a greater effectiveness of the groups with cognitive-behavioural orientation, but confirm that psychotherapeutic groups in psychiatric contexts, even in emergency, not only seems to be well accepted and perceived positively by users and family members, but it also contributes to increasing satisfaction with the ward.


Subject(s)
Cognitive Behavioral Therapy , Mood Disorders/therapy , Personality Disorders/therapy , Psychoanalytic Therapy , Psychotherapy, Group , Psychotic Disorders/therapy , Adult , Family Health , Female , Humans , Male , Middle Aged , Treatment Outcome
14.
Ann Ist Super Sanita ; 56(2): 171-179, 2020.
Article in English | MEDLINE | ID: mdl-32567567

ABSTRACT

Many young adults with neurodevelopmental disorders experience poor transition outcomes in key areas, including employment, health care, and independent living. Innovative welfare models highlight the importance of involving the local community, and in particular the parents, as important stakeholders capable to generate services and affect local economy. As indicated by the World Health Organization, the availability of person-centered responses, also providing a health budget, appears to be the basis for taking into account person's rights to self-determination. Health services and local stakeholders could play an important role to facilitate the implementation of support networks that are functional for an effective social inclusion. In order to improve current practices in transitioning to adulthood, it is of paramount importance to collect and learn from the living experience of people with neurodevelopmental disabilities and their families.


Subject(s)
Developmental Disabilities , Parents , Patient Care Planning , Adult , Child , Female , Humans , Italy , Male , Personal Autonomy
15.
Int J Mol Sci ; 21(4)2020 Feb 12.
Article in English | MEDLINE | ID: mdl-32059382

ABSTRACT

Conductance of CO2 across the mesophyll (Gm) frequently constrains photosynthesis (PN) but cannot be measured directly. We examined Gm of cherry (Prunus avium L.) subjected to severe drought using the variable J method and carbon-isotopic composition (δ13C) of sugars from the centre of the leaf, the leaf petiole sap, and sap from the largest branch. Depending upon the location of the plant from which sugars are sampled, Gm may be estimated over scales ranging from a portion of the leaf to a canopy of leaves. Both the variable J and δ13C of sugars methods showed a reduction in Gm as soil water availability declined. The δ13C of sugars further from the source of their synthesis within the leaf did not correspond as closely to the diffusive and C-isotopic discrimination conditions reflected in the instantaneous measurement of gas exchange and chlorophyll-fluorescence utilised by the variable J approach. Post-photosynthetic fractionation processes and/or the release of sugars from stored carbohydrates (previously fixed under different environmental and C-isotopic discrimination conditions) may reduce the efficacy of the δ13C of sugars from leaf petiole and branch sap in estimating Gm in a short-term study. Consideration should be given to the spatial and temporal scales at which Gm is under observation in any experimental analysis.


Subject(s)
Carbon Isotopes/metabolism , Droughts , Mesophyll Cells/metabolism , Plant Leaves/metabolism , Prunus avium/metabolism , Sugars/metabolism , Carbon Dioxide/chemistry , Carbon Dioxide/metabolism , Chlorophyll/metabolism , Models, Biological , Photosynthesis/physiology , Soil , Sugars/chemistry , Water
16.
Ann Bot ; 124(4): 627-644, 2019 10 29.
Article in English | MEDLINE | ID: mdl-30715123

ABSTRACT

BACKGROUND AND AIMS: Hydraulic and chemical signals operate in tandem to regulate systemic plant responses to drought. Transport of abscisic acid (ABA) through the xylem and phloem from the root to shoot has been suggested to serve as the main signal of water deficit. There is evidence that ABA and its ABA-glycosyl-ester (ABA-GE) are also formed in leaves and stems through the chloroplastic 2-C-methylerythritol-5-phosphate (MEP) pathway. This study aimed to evaluate how hormonal and hydraulic signals contribute to optimize stomatal (gs), mesophyll (gm) and leaf hydraulic (Kleaf) conductance under well-watered and water-stressed conditions in Populus nigra (black poplar) plants. In addition, we assessed possible relationships between ABA and soluble carbohydrates within the leaf and stem. METHODS: Plants were subjected to three water treatments: well-watered (WW), moderate stress (WS1) and severe stress (WS2). This experimental set-up enabled a time-course analysis of the response to water deficit at the physiological [leaf gas exchange, plant water relations, (Kleaf)], biochemical (ABA and its metabolite/catabolite quantification in xylem sap, leaves, wood, bark and roots) and molecular (gene expression of ABA biosynthesis) levels. KEY RESULTS: Our results showed strong coordination between gs, gm and Kleaf under water stress, which reduced transpiration and increased intrinsic water use efficiency (WUEint). Analysis of gene expression of 9-cis-epoxycarotenoid dioxygenase (NCED) and ABA content in different tissues showed a general up-regulation of the biosynthesis of this hormone and its finely-tuned catabolism in response to water stress. Significant linear relationships were found between soluble carbohydrates and ABA contents in both leaves and stems, suggesting a putative function for this hormone in carbohydrate mobilization under severe water stress. CONCLUSIONS: This study demonstrates the tight regulation of the photosynthetic machinery by levels of ABA in different plants organs on a daily basis in both well-watered and water stress conditions to optimize WUEint and coordinate whole plant acclimation responses to drought.


Subject(s)
Abscisic Acid , Populus , Carbohydrates , Carbon Cycle , Dehydration , Humans , Plant Leaves , Plant Roots , Plant Stomata , Plant Transpiration , Water
17.
Ann Bot ; 124(4): 567-580, 2019 10 29.
Article in English | MEDLINE | ID: mdl-30566593

ABSTRACT

BACKGROUND AND AIMS: The development of Arundo donax as a biomass crop for use on drought-prone marginal lands in areas with warm to hot climates is constrained by the lack of variation within this species. We investigated the effect of morphological and physiological variation on growth and tolerance to drought under field conditions in three ecotypes of A. donax collected from habitats representing a climate gradient: a pre-desert in Morocco, a semi-arid Mediterranean climate in southern Italy and a warm sub-humid region of central Italy. METHODS: The three A. donax ecotypes were grown under irrigated and rain-fed conditions in a common garden field trial in a region with a semi-arid Mediterranean climate. Physiological and morphological characteristics, and carbohydrate metabolism of the ecotypes were recorded to establish which traits were associated with yield and/or drought tolerance. KEY RESULTS: Variation was observed between the A. donax ecotypes. The ecotype from the most arid habitat produced the highest biomass yield. Stem height and the retention of photosynthetic capacity later in the year were key traits associated with differences in biomass yield. The downregulation of photosynthetic capacity was not associated with changes in foliar concentrations of sugars or starch. Rain-fed plants maintained photosynthesis and growth later in the year compared with irrigated plants that began to senescence earlier, thus minimizing the difference in yield. Effective stomatal control prevented excessive water loss, and the emission of isoprene stabilized photosynthetic membranes under drought and heat stress in A. donax plants grown under rain-fed conditions without supplementary irrigation. CONCLUSIONS: Arundo donax is well adapted to cultivation in drought-prone areas with warm to hot climates. None of the A. donax ecotypes exhibited all of the desired traits consistent with an 'ideotype'. Breeding or genetic (identification of quantitative trait loci) improvement of A. donax should select ecotypes on the basis of stem morphology and the retention of photosynthetic capacity.


Subject(s)
Droughts , Photosynthesis , Italy , Poaceae , Seasons
18.
Conserv Physiol ; 7(1): coz070, 2019.
Article in English | MEDLINE | ID: mdl-32467757

ABSTRACT

Maquis species play a central role in the maintenance of coastal ecosystems thanks to anatomical, physiological and biochemical features evolved to cope with severe stress conditions. Because the seasonal and daily dynamics of physiological and biochemical traits of maquis species are not fully addressed, we performed a field study on three coexisting Mediterranean shrubs (Pistacia lentiscus L. and Phillyrea latifolia L., evergreen schlerophylls, and Cistus incanus L., semi-deciduous) aiming at detecting the main adaptive differences, on a seasonal and daily basis, in primary and secondary metabolism along with the principal climatic determinants. These species differed in their physiological and biochemical responses especially on a seasonal level. In P. latifolia, a great investment in antioxidant phenylpropanoids contributed to maintain high photosynthetic rates throughout the whole growing season. In C. incanus, high carotenoid content associated with chlorophyll (Chl) regulation alleviated oxidative damage during the hot and dry summers and help recover photosynthesis in autumn. In P. lentiscus, high abscisic acid levels allowed a strict control of stomata, while fine Chla/Chlb regulation concurred to avoid photoinhibition in summer. Temperature resulted the most important climatic factor controlling the physiological and biochemical status of these coexisting shrubs and, thus, in determining plant performances in this Mediterranean coastal habitat.

19.
Plants (Basel) ; 7(4)2018 Sep 20.
Article in English | MEDLINE | ID: mdl-30241389

ABSTRACT

Heat waves are predicted to increase in frequency and duration in many regions as global temperatures rise. These transient increases in temperature above normal average values will have pronounced impacts upon the photosynthetic and stomatal physiology of plants. During the summer of 2017, much of the Mediterranean experienced a severe heat wave. Here, we report photosynthetic leaf gas exchange and chlorophyll fluorescence parameters of olive (Olea europaea cv. Leccino) grown under water deficit and full irrigation over the course of the heat wave as midday temperatures rose over 40 °C in Central Italy. Heat stress induced a decline in the photosynthetic capacity of the olives consistent with reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity. Damage to photosystem II was more apparent in plants subject to water deficit. In contrast to previous studies, higher temperatures induced reductions in stomatal conductance. Heat stress adversely affected the carbon efficiency of olive. The selection of olive varieties with enhanced tolerance to heat stress and/or strategies to mitigate the impact of higher temperatures will become increasingly important in developing sustainable agriculture in the Mediterranean as global temperatures rise.

20.
Colloids Surf B Biointerfaces ; 163: 1-8, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29268209

ABSTRACT

This paper describes the development of a facile and environmentally friendly strategy for supporting crotamine on gold nanoparticles (GNPs). Our approach was based on the covalent binding interaction between the cell penetrating peptide crotamine, which is a snake venom polypeptide with preference to penetrate dividing cells, and a polyethylene glycol (PEG) ligand, which is a nontoxic, water-soluble and easily obtainable commercial polymer. Crotamine was derivatized with ortho-pyridyldisulfide-polyethyleneglycol-N-hydroxysuccinimide (OPSS-PEG-SVA) cross-linker to produce OPSS-PEG-crotamine as the surface modifier of GNP. OPSS-PEG-SVA can serve not only as a surface modifier, but also as a stabilizing agent for GNPs. The successful PEGylation of the nanoparticles was demonstrated using different physicochemical techniques, while the grafting densities of the PEG ligands and crotamine on the surface of the nanoparticles were estimated using a combination of electron microscopy and mass spectrometry analysis. In vitro assays confirmed the internalization of these GNPs, into living HeLa cells. The results described herein suggest that our approach may serve as a simple platform for the synthesis of GNPs decorated with crotamine with well-defined morphologies and uniform dispersion, opening new roads for crotamine biomedical applications.


Subject(s)
Antineoplastic Agents/pharmacology , Cell-Penetrating Peptides/pharmacology , Crotalid Venoms/pharmacology , Drug Carriers , Gold/chemistry , Polyethylene Glycols/chemistry , 2,2'-Dipyridyl/analogs & derivatives , 2,2'-Dipyridyl/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Biological Transport , Cell Proliferation/drug effects , Cell-Penetrating Peptides/chemistry , Cell-Penetrating Peptides/metabolism , Cross-Linking Reagents/chemistry , Crotalid Venoms/chemistry , Crotalid Venoms/metabolism , Disulfides/chemistry , HeLa Cells , Humans , Metal Nanoparticles/ultrastructure , Succinimides/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL