90 research outputs found

    The Effects of Crop Type and Production Systems on the Activity of Beneficial Invertebrates

    Get PDF
    Beneficial invertebrate activity (13 groups) was assessed in five crop types on a split-plot experimental system in northern England using pitfall trapping and suction sampling in May-October 2005. Very significant differences were detected in activity between crop type, and in the preference of groups for individual crops. Within crop types, differences in fertiliser and crop protection approaches appeared to significantly affect activity, with preferences for either organic or conventional management differing between groups. In general, inorganic fertiliser application had more effect on activity than pesticide, herbicide and fungicide use

    The influence of organic and conventional fertilisation and crop protection practices, preceding crop, harvest year and weather conditions on yield and quality of potato (Solanum tuberosum) in a long-term management trial

    Get PDF
    The effects of organic versus conventional crop management practices (fertilisation, crop protection) and preceding crop on potato tuber yield (total, marketable, tuber size grade distribution) and quality (proportion of diseased, green and damaged tubers, tuber macro-nutrient concentrations) parameters were investigated over six years (2004–2009) as part of a long-term factorial field trial in North East England. Inter-year variability (the effects of weather and preceding crop) was observed to have a profound effect on yields and quality parameters, and this variability was greater in organic fertility systems. Total and marketable yields were significantly reduced by the use of both organic crop protection and fertility management. However, the yield gap between organic and conventional fertilisation regimes was greater and more variable than that between crop protection practices. This appears to be attributable mainly to lower and less predictable nitrogen supply in organically fertilised crops. Increased incidence of late blight in organic crop protection systems only occurred when conventional fertilisation was applied. In organically fertilised crops yield was significantly higher following grass/red clover leys than winter wheat, but there was no pre-crop effect in conventionally fertilised crops. The results highlight that nitrogen supply from organic fertilisers rather than inefficient pest and disease control may be the major limiting factor for yields in organic potato production systems

    Effect of Climate, Crop Protection, and Fertilization on Disease Severity, Growth, and Grain Yield Parameters of Faba Beans (<em>Vicia faba</em> L.) in Northern Britain: Results from the Long-Term NFSC Trials

    Get PDF
    \ua9 2024 by the authors. Faba beans are one of the most suitable grain legume crop for colder, maritime climates. However, there is limited information on the effect of changing from conventional to organic production methods and potential impacts of global warming on the health and performance of faba bean crops in Northern Europe. We therefore assessed the performance of faba beans grown with contrasting crop protection (with and without pesticides) and fertilization (with and without P and K fertilizer input) regimes used in organic and conventional production in seven growing seasons. Conventional crop protection and fertilization regimes had no effect on foliar disease severity, but resulted in small, but significant increases in faba bean yields. The overall yield gap between organic and conventional production regimes was relatively small (~10%), but there was substantial variation in yields between growing seasons/years. Redundancy analysis (RDA) showed that climate explanatory variables/drivers explained the largest proportion of the variation in crop performance and identified strong positive associations between (i) temperature and both straw and grain yield and (ii) precipitation and foliar disease severity. However, RDA also identified crop protection and variety as significant explanatory variables for faba bean performance. The relatively small effect of using P and K fertilizers on yields and the lack of a measurable effect of fungicide applications on foliar disease severity indicate that the use of these inputs in conventional faba beans may not be economical. Results also suggest that the yield gap between organic and conventional faba bean production is significant, but smaller than for other field crops

    Effects of Climatic Conditions and Agronomic Practices on Health, Tuber Yield, and Mineral Composition of Two Contrasting Potato Varieties Developed for High and Low Input Production Systems

    Get PDF
    \ua9 2024 by the authors.Modern potato varieties from high-input, conventional farming-focused breeding programs produce substantially (up to 45%) lower yields when grown in organic production systems, and this was shown to be primarily due to less efficient fertilization and late blight (Phytophthora infestans) control methods being used in organic farming. It has been hypothesized that the breeding of potato varieties suitable for the organic/low-input sector should (i) focus on increasing nutrient (especially N) use efficiency, (ii) introduce durable late blight resistance, and (iii) be based on selection under low-input conditions. To test this hypothesis, we used an existing long-term factorial field experiment (the NEFG trials) to assess the effect of crop management practices (rotation design, fertilization regime, and crop protection methods) used in conventional and organic farming systems on crop health, tuber yield, and mineral composition parameters in two potato varieties, Sant\ue9 and Sarpo mira, that were developed in breeding programs for high and low-input farming systems, respectively. Results showed that, compared to Sant\ue9, the variety Sarpo mira was more resistant to foliar and tuber blight but more susceptible to potato scab (Streptomyces scabies) and produced higher yields and tubers with higher concentrations of nutritionally desirable mineral nutrients but lower concentrations of Cd. The study also found that, compared to the Cu-fungicides permitted for late blight control in organic production, application of synthetic chemical fungicides permitted and widely used in conventional production resulted in significantly lower late blight severity in Sante but not in Sarpo mira. Results from both ANOVA and redundancy analysis (RDA) indicate that the effects of climatic (precipitation, radiation, and temperature) and agronomic (fertilization and crop protection) explanatory variables on crop health and yield differed considerably between the two varieties. Specifically, the RDA identified crop protection as a significant driver for Sant\ue9 but not Sarpo mira, while precipitation was the strongest driver for crop health and yield for Sarpo mira but not Sant\ue9. In contrast, the effect of climatic and agronomic drivers on tuber mineral and toxic metal concentrations in the two varieties was found to be similar. Our results support the hypothesis that selection of potato varieties under low agrochemical input conditions can deliver varieties that combine (i) late blight resistance/tolerance, (ii) nutrient use efficiency, and (iii) yield potential in organic farming systems

    Profile of MicroRNAs following Rat Sciatic Nerve Injury by Deep Sequencing: Implication for Mechanisms of Nerve Regeneration

    Get PDF
    Unlike the central nervous system, peripheral nerves can regenerate when damaged. MicroRNA (miRNA) is a novel class of small, non-coding RNA that regulates gene expression at the post-transcriptional level. Here, we report regular alterations of miRNA expression following rat sciatic nerve injury using deep sequencing. We harvested dorsal root ganglia tissues and the proximal stumps of the nerve, and identified 201 and 225 known miRNAs with significant expression variance at five time points in these tissues after sciatic nerve transaction, respectively. Subsequently, hierarchical clustering, miRNA expression pattern and co-expression network were performed. We screened out specific miRNAs and further obtained the intersection genes through target analysis software (Targetscan and miRanda). Moreover, GO and KEGG enrichment analyses of these intersection genes were performed. The bioinformatics analysis indicated that the potential targets for these miRNAs were involved in nerve regeneration, including neurogenesis, neuron differentiation, vesicle-mediated transport, homophilic cell adhesion and negative regulation of programmed cell death that were known to play important roles in regulating nerve repair. Finally, we combined differentially expressed mRNA with the predicted targets for selecting inverse miRNA-target pairs. Our results show that the abnormal expression of miRNA may contribute to illustrate the molecular mechanisms of nerve regeneration and that miRNAs are potential targets for therapeutic interventions and may enhance intrinsic regenerative ability

    Rasd1 Modulates the Coactivator Function of NonO in the Cyclic AMP Pathway

    Get PDF
    All living organisms exhibit autonomous daily physiological and behavioural rhythms to help them synchronize with the environment. Entrainment of circadian rhythm is achieved via activation of cyclic AMP (cAMP) and mitogen-activated protein kinase signaling pathways. NonO (p54nrb) is a multifunctional protein involved in transcriptional activation of the cAMP pathway and is involved in circadian rhythm control. Rasd1 is a monomeric G protein implicated to play a pivotal role in potentiating both photic and nonphotic responses of the circadian rhythm. In this study, we have identified and validated NonO as an interacting partner of Rasd1 via affinity pulldown, co-immunoprecipitation and indirect immunofluorescence studies. The GTP-hydrolysis activity of Rasd1 is required for the functional interaction. Functional interaction of Rasd1-NonO in the cAMP pathway was investigated via reporter gene assays, chromatin immunoprecipitation and gene knockdown. We showed that Rasd1 and NonO interact at the CRE-site of specific target genes. These findings reveal a novel mechanism by which the coregulator activity of NonO can be modulated

    Early phase of plasticity-related gene regulation and SRF dependent transcription in the hippocampus

    Get PDF
    Hippocampal organotypic cultures are a highly reliable in vitro model for studying neuroplasticity: in this paper, we analyze the early phase of the transcriptional response induced by a 20 \ub5M gabazine treatment (GabT), a GABA-Ar antagonist, by using Affymetrix oligonucleotide microarray, RT-PCR based time-course and chromatin-immuno-precipitation. The transcriptome profiling revealed that the pool of genes up-regulated by GabT, besides being strongly related to the regulation of growth and synaptic transmission, is also endowed with neuro-protective and pro-survival properties. By using RT-PCR, we quantified a time-course of the transient expression for 33 of the highest up-regulated genes, with an average sampling rate of 10 minutes and covering the time interval [10 3690] minutes. The cluster analysis of the time-course disclosed the existence of three different dynamical patterns, one of which proved, in a statistical analysis based on results from previous works, to be significantly related with SRF-dependent regulation (p-value<0.05). The chromatin immunoprecipitation (chip) assay confirmed the rich presence of working CArG boxes in the genes belonging to the latter dynamical pattern and therefore validated the statistical analysis. Furthermore, an in silico analysis of the promoters revealed the presence of additional conserved CArG boxes upstream of the genes Nr4a1 and Rgs2. The chip assay confirmed a significant SRF signal in the Nr4a1 CArG box but not in the Rgs2 CArG box

    NR4A orphan nuclear receptors in immediate early regulation of retinoid signaling and neuroprotection [Elektronisk resurs]

    No full text
    NR4A receptors show distinct properties that make them unique within the family of nuclear receptors. They lack a ligand-binding cavity and a canonical coactivator-binding site and they are induced both in vivo and in vitro in an immediate early way by an extremely wide repertoire of substances/conditions. Apart from their specific roles during development, they play crucial, yet not fully charazterized, roles in sensing of and responding to changes in the cellular environment. In paper I, we provide novel insights into the mechanism of NR4A-mediated transcription by identifying an alternative coactivator-binding surface that is unique to the NR4A family of nuclear receptors. We also report a link between NR4A transcriptional activity and protein turnover and identify protein sequence differences between the NR4A receptor members that may account for their differential transcriptional activity. In paper II, we provide evidence suggesting that NR4A receptors can influence signaling events of other nuclear receptors via inducing the expression of fatty acid binding protein 5. Specifically, NR4A receptors can enhance retinoic acid-induced signaling of the peroxisome proliferator-activated receptor and docosahexaenoic acid-induced activation of the retinoid X receptor. In paper III, we demonstrate that NR4A proteins are induced by cyclic AMP response element binding protein (CREB) in neurons exposed to excitotoxic and oxidative insults and that they function as mediators of CREB-induced neuronal survival by inducing the expression of a battery of neuroprotective genes. Moreover, we show that mice with null mutations in three out of six NR4A alleles show increased oxidative damage, blunted induction of neuroprotective genes and increased vulnerability in the hippocampus after treatment with the excitotoxin kainic acid. In summary, we show that NR4A receptors utilize a distinct surface to bind coactivators, that they can influence signaling by two other nuclear receptors by upregulating a fatty acid binding protein and that they are essential mediators of neuroprotection after exposure to neuropathological stress
    corecore