167 research outputs found
Environmental sustainability fruit quality and production in mycorrhizal tomato plants without P fertilizing
The influence of root colonization by arbuscular mycorrhizal (AM) fungus
Funelliformis mosseae, on fruit quality, production and environmental sustainability were
evaluated in field-tomato plants grown exposed to P-limited soil 5 µg g
-1
soil (basal-soil) with
nitrate fertilization (50 µg g
-1
soil), after greenhouse germination and fungus colonization. After
60 days sowing (DAS), when the percentage of mycorrhizal root length (% RLC) raised at about
50%, the plants were transplanted in open field.
During the experiment, the mycorrhization has affected a lot of physiological aspects like
vegetative and reproductive growth, improving them and ended the fruiting with a major fruit
production that was 50% higher than not mycorrhizal (NM) plants. The ripening process of the
fruits was also followed by testing sugars content and ß-Amylase activity in fruits of NM and
mycorrhizal (M) plants fruits. At 140 DAS, in the harvesting fruits stage, fruits of M plants
showed significantly higher mineral nutrient sugars and organic nitrogen compounds as amino
acids and protein, compared to fruits from NM plants. In particular, GLU-GLN-ASP and ASN
raised about 35% more than fruits from NM plants, improving nutritional aspect and flavor of the
product. THR-ILEU-LEU-VAL and LYS, essential amino acids in man nutrition, increased
around 25% more than fruits from NM plants, too. In this contest, lycopene, total carotenoids,
ascorbic acid and glutathione (GS) and reduced form (GSH) were also tested in ripe fruits. The
overall results suggest that tomato roots colonization by mycorrhizal fungus Funelliformis
mosseae affects host plant nutritional status, modifying reproductive behavior, fruits production
and nutritional quality
The Neuropeptide PDF Acts Directly on Evening Pacemaker Neurons to Regulate Multiple Features of Circadian Behavior
Animals use distinct sets of clock neurons to time behaviors in the morning and evening. In this article, the direct neural targets for morning neurons and the neuropeptide pigment dispersing factor are revealed in the fruit fly
Neural correlates of sexual cue reactivity in individuals with and without compulsive sexual behaviours
Although compulsive sexual behaviour (CSB) has been conceptualized as a "behavioural" addiction and common or overlapping neural circuits may govern the processing of natural and drug rewards, little is known regarding the responses to sexually explicit materials in individuals with and without CSB. Here, the processing of cues of varying sexual content was assessed in individuals with and without CSB, focusing on neural regions identified in prior studies of drug-cue reactivity. 19 CSB subjects and 19 healthy volunteers were assessed using functional MRI comparing sexually explicit videos with non-sexual exciting videos. Ratings of sexual desire and liking were obtained. Relative to healthy volunteers, CSB subjects had greater desire but similar liking scores in response to the sexually explicit videos. Exposure to sexually explicit cues in CSB compared to non-CSB subjects was associated with activation of the dorsal anterior cingulate, ventral striatum and amygdala. Functional connectivity of the dorsal anterior cingulate-ventral striatum-amygdala network was associated with subjective sexual desire (but not liking) to a greater degree in CSB relative to non-CSB subjects. The dissociation between desire or wanting and liking is consistent with theories of incentive motivation underlying CSB as in drug addictions. Neural differences in the processing of sexual-cue reactivity were identified in CSB subjects in regions previously implicated in drug-cue reactivity studies. The greater engagement of corticostriatal limbic circuitry in CSB following exposure to sexual cues suggests neural mechanisms underlying CSB and potential biological targets for interventions
PDFR and CRY Signaling Converge in a Subset of Clock Neurons to Modulate the Amplitude and Phase of Circadian Behavior in Drosophila
Background: To synchronize their molecular rhythms, circadian pacemaker neurons must input both external and internal timing cues and, therefore, signal integration between sensory information and internal clock status is fundamental to normal circadian physiology. Methodology/Principal Findings: We demonstrate the specific convergence of clock-derived neuropeptide signaling with that of a deep brain photoreceptor. We report that the neuropeptide PDF receptor and the circadian photoreceptor CRYPTOCROME (CRY) are precisely co-expressed in a subset of pacemakers, and that these pathways together provide a requisite drive for circadian control of daily locomotor rhythms. These convergent signaling pathways influence the phase of rhythm generation, but also its amplitude. In the absence of both pathways, PER rhythms were greatly reduced in only those specific pacemakers that receive convergent inputs and PER levels remained high in the nucleus throughout the day. This suggested a large-scale dis-regulation of the pacemaking machinery. Behavioral rhythms were likewise disrupted: in light:dark conditions they were aberrant, and under constant dark conditions, they were lost. Conclusions/Significance: We speculate that the convergence of environmental and clock-derived signals may produce
The Circadian Neuropeptide PDF Signals Preferentially through a Specific Adenylate Cyclase Isoform AC3 in M Pacemakers of Drosophila
To synchronize a network of pacemakers in the Drosophila brain, a neuropeptide receptor specifically associates with adenylate cyclase 3 to create a “circadian signalosome.
Prendersi cura della generatività,genitorialità e cogenitorialità con gli operatori socio-sanitari per una profilassi psicoeducativa
Adult Circadian Behavior in Drosophila Requires Developmental Expression of cycle, But Not period
Circadian clocks have evolved as internal time keeping mechanisms that allow anticipation of daily environmental changes and organization of a daily program of physiological and behavioral rhythms. To better examine the mechanisms underlying circadian clocks in animals and to ask whether clock gene expression and function during development affected subsequent daily time keeping in the adult, we used the genetic tools available in Drosophila to conditionally manipulate the function of the CYCLE component of the positive regulator CLOCK/CYCLE (CLK/CYC) or its negative feedback inhibitor PERIOD (PER). Differential manipulation of clock function during development and in adulthood indicated that there is no developmental requirement for either a running clock mechanism or expression of per. However, conditional suppression of CLK/CYC activity either via per over-expression or cyc depletion during metamorphosis resulted in persistent arrhythmic behavior in the adult. Two distinct mechanisms were identified that may contribute to this developmental function of CLK/CYC and both involve the ventral lateral clock neurons (LNvs) that are crucial to circadian control of locomotor behavior: (1) selective depletion of cyc expression in the LNvs resulted in abnormal peptidergic small-LNv dorsal projections, and (2) PER expression rhythms in the adult LNvs appeared to be affected by developmental inhibition of CLK/CYC activity. Given the conservation of clock genes and circuits among animals, this study provides a rationale for investigating a possible similar developmental role of the homologous mammalian CLOCK/BMAL1 complex
Perturbing Dynamin Reveals Potent Effects on the Drosophila Circadian Clock
BACKGROUND: Transcriptional feedback loops are central to circadian clock function. However, the role of neural activity and membrane events in molecular rhythms in the fruit fly Drosophila is unclear. To address this question, we expressed a temperature-sensitive, dominant negative allele of the fly homolog of dynamin called shibire(ts1) (shi(ts1)), an active component in membrane vesicle scission. PRINCIPAL FINDINGS: Broad expression in clock cells resulted in unexpectedly long, robust periods (>28 hours) comparable to perturbation of core clock components, suggesting an unappreciated role of membrane dynamics in setting period. Expression in the pacemaker lateral ventral neurons (LNv) was necessary and sufficient for this effect. Manipulation of other endocytic components exacerbated shi(ts1)'s behavioral effects, suggesting its mechanism is specific to endocytic regulation. PKA overexpression rescued period effects suggesting shi(ts1) may downregulate PKA pathways. Levels of the clock component PERIOD were reduced in the shi(ts1)-expressing pacemaker small LNv of flies held at a fully restrictive temperature (29 degrees C). Less restrictive conditions (25 degrees C) delayed cycling proportional to observed behavioral changes. Levels of the neuropeptide PIGMENT-DISPERSING FACTOR (PDF), the only known LNv neurotransmitter, were also reduced, but PERIOD cycling was still delayed in flies lacking PDF, implicating a PDF-independent process. Further, shi(ts1) expression in the eye also results in reduced PER protein and per and vri transcript levels, suggesting that shibire-dependent signaling extends to peripheral clocks. The level of nuclear CLK, transcriptional activator of many core clock genes, is also reduced in shi(ts1) flies, and Clk overexpression suppresses the period-altering effects of shi(ts1). CONCLUSIONS: We propose that membrane protein turnover through endocytic regulation of PKA pathways modulates the core clock by altering CLK levels and/or activity. These results suggest an important role for membrane scission in setting circadian period
Prospective longitudinal associations between persistent sleep problems in childhood and anxiety and depression disorders in adulthood
The objective of this study was to examine the associations between persistent childhood sleep problems and adulthood anxiety and depression. Parents of 943 children (52% male) participating in the Dunedin Multidisciplinary Health and Development Study provided information on their children’s sleep and internalizing problems at ages 5, 7, and 9 years. When the participants were 21 and 26 years, adult anxiety and depression were diagnosed using a standardized diagnostic interview. After controlling for childhood internalizing problems, sex, and socioeconomic status, persistent sleep problems in childhood predicted adulthood anxiety disorders (OR (95% CI) = 1.60 (1.05– 2.45), p = .030) but not depressive disorders (OR (95% CI) = .99 (.63–1.56), p = .959). Persistent sleep problems in childhood may be an early risk indicator of anxiety in adulthood
CRTC Potentiates Light-independent timeless Transcription to Sustain Circadian Rhythms in Drosophila
Light is one of the strongest environmental time cues for entraining endogenous circadian rhythms. Emerging evidence indicates that CREB-regulated transcription co-activator 1 (CRTC1) is a key player in this pathway, stimulating light-induced Period1 (Per1) transcription in mammalian clocks. Here, we demonstrate a light-independent role of Drosophila CRTC in sustaining circadian behaviors. Genomic deletion of the crtc locus causes long but poor locomotor rhythms in constant darkness. Overexpression or RNA interference-mediated depletion of CRTC in circadian pacemaker neurons similarly impairs the free-running behavioral rhythms, implying that Drosophila clocks are sensitive to the dosage of CRTC. The crtc null mutation delays the overall phase of circadian gene expression yet it remarkably dampens light-independent oscillations of TIMELESS (TIM) proteins in the clock neurons. In fact, CRTC overexpression enhances CLOCK/CYCLE (CLK/CYC)-activated transcription from tim but not per promoter in clock-less S2 cells whereas CRTC depletion suppresses it. Consistently, TIM overexpression partially but significantly rescues the behavioral rhythms in crtc mutants. Taken together, our data suggest that CRTC is a novel co-activator for the CLK/CYC-activated tim transcription to coordinate molecular rhythms with circadian behaviors over a 24-hour time-scale. We thus propose that CRTC-dependent clock mechanisms have co-evolved with selective clock genes among different species.ope
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