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1.
Physiother Theory Pract ; : 1-12, 2023 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-38145499

RESUMO

OBJECTIVE: Digital technology has become increasingly relevant in physiotherapy, but little is known about communication and interaction in video-based physiotherapy. Therefore, this study aimed to explore the experiences among patients and physiotherapists, of communication and interaction in digital, video-based physiotherapy. METHODS: A qualitative interview study with a phenomenological approach was conducted. Participants were purposively recruited from primary health care clinics. Semi-structured, in-depth interviews were conducted with 10 physiotherapists and 6 patients. Interviews were recorded, transcribed, and analyzed using a phenomenological approach. RESULTS: The analysis resulted in the overall theme Reaching for connection, which captured the central meaning of the participants' experiences. Four categories emerged from the analysis: 1) Closeness at a distance; 2) Overcoming limited bodily communication; 3) The technology as part of the meeting; and 4) Challenging the physical meeting as a norm. The results suggest that communication and interaction in digital settings differ from physical settings, but there is an ongoing adaptation process to this new paradigm. CONCLUSIONS: The results of this study show that video-based physiotherapy, while having several benefits according to both patients and physiotherapists, affects the communication in several ways. Physiotherapists need to acknowledge these limitations and seek strategies to adapt and to compensate for the reduced non-verbal elements and lack of touch. Attention to the physical room and shifting between positions (face/full figure) are suggested practical strategies, but also to practice awareness and embodied communication to improve receptivity in the interaction.

2.
BMC Womens Health ; 23(1): 618, 2023 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980530

RESUMO

BACKGROUND: Childbirth is one of the biggest risk factors for incontinence. Urinary and anal incontinence can cause pain and social limitations that affect social life, cohabitation, and work. There is currently no up-to-date literature study on the effect of pelvic floor muscle training with feedback from a physiotherapist, which involves verbal instructions based on vaginal and anal digital palpation, compared to treatment without feedback (e.g., recommendations for pelvic floor muscle training). AIM: The objective of this systematic review was to examine the scientific evidence regarding the impact of pelvic floor muscle training (PFMT) with feedback from a physiotherapist and/or biofeedback on urinary and anal incontinence in women during the first six months following vaginal delivery, compared to treatment without feedback. METHODS: The literature search was conducted in the databases PubMed, Cochrane, and CINAHL. In addition, a manual search was conducted. The search terms consisted of MeSH terms and synonyms in the respective search block including population, intervention, and study design, as well as the terms pelvic floor and postpartum. An evaluation of each included study was conducted for methodological quality, evidence value, and clinical relevance. RESULTS: Eight studies were included, three of which showed a significant difference between groups, in favor of the intervention group that received pelvic floor muscle training with feedback from a physiotherapist and/or biofeedback. Due to the varying results and insufficient quality for the majority of the studies, the scientific basis was considered insufficient. CONCLUSION: The scientific evidence for pelvic floor muscle training with feedback from a physiotherapist or biofeedback on postpartum urinary and anal incontinence compared to treatment without feedback is considered insufficient. Further research on the subject is needed. The study is registered in PROSPERO CRD42022361296.


Assuntos
Incontinência Fecal , Fisioterapeutas , Incontinência Urinária por Estresse , Gravidez , Feminino , Humanos , Diafragma da Pelve , Retroalimentação , Terapia por Exercício/métodos , Biorretroalimentação Psicológica , Parto Obstétrico , Incontinência Fecal/etiologia , Incontinência Fecal/terapia , Incontinência Urinária por Estresse/terapia , Resultado do Tratamento
3.
PLoS One ; 18(3): e0283013, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36943857

RESUMO

BACKGROUND: This systematic review aimed to assess the certainty of evidence for digital versus conventional, face-to-face physiotherapy assessment of musculoskeletal disorders, concerning validity, reliability, feasibility, patient satisfaction, physiotherapist satisfaction, adverse events, clinical management, and cost-effectiveness. METHODS: Eligibility criteria: Original studies comparing digital physiotherapy assessment with face-to-face physiotherapy assessment of musculoskeletal disorders. Systematic database searches were performed in May 2021, and updated in May 2022, in Medline, Cochrane Library, Cinahl, AMED, and PEDro. Risk of bias and applicability of the included studies were appraised using the Quality Assessment of Diagnostic Accuracy Studies-2 tool and the Quality Appraisal of Reliability Studies tool. Included studies were synthesised narratively. Certainty of evidence was evaluated for each assessment component using GRADE. RESULTS: Ten repeated-measures studies were included, involving 193 participants aged 23-62 years. Reported validity of digital physiotherapy assessment ranged from moderate/acceptable to almost perfect/excellent for clinical tests, range of motion, patient-reported outcome measures (PROMs), pain, neck posture, and management decisions. Reported validity for assessing spinal posture varied and was for clinical observations unacceptably low. Reported validity and reliability for digital diagnosis ranged from moderate to almost perfect for exact+similar agreement, but was considerably lower when constrained to exact agreement. Reported reliability was excellent for digital assessment of clinical tests, range of motion, pain, neck posture, and PROMs. Certainty of evidence varied from very low to high, with PROMs and pain assessment obtaining the highest certainty. Patients were satisfied with their digital assessment, but did not perceive it as good as face-to-face assessment. DISCUSSION: Evidence ranging from very low to high certainty suggests that validity and reliability of digital physiotherapy assessments are acceptable to excellent for several assessment components. Digital physiotherapy assessment may be a viable alternative to face-to-face assessment for patients who are likely to benefit from the accessibility and convenience of remote access. TRIAL REGISTRATION: The review was registered in the PROSPERO database, CRD42021277624.


Assuntos
Doenças Musculoesqueléticas , Cervicalgia , Humanos , Reprodutibilidade dos Testes , Doenças Musculoesqueléticas/diagnóstico , Doenças Musculoesqueléticas/terapia , Satisfação do Paciente , Modalidades de Fisioterapia
5.
Eur Rev Aging Phys Act ; 17: 10, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32699561

RESUMO

BACKGROUND: Physical activity and exercise are acknowledged as important parts in the management of rheumatoid arthritis (RA). However, long-term maintenance of exercise is known to be difficult. The aim of this study was to evaluate change in physical activity and physical fitness after four years in older adults with RA who had previously participated in exercise with person-centred guidance compared to controls. METHOD: A follow-up study was performed where older adults (> 65 years) who had participated in a randomized controlled trial where they were allocated to either exercise with person-centred guidance or home-based, light-intensity exercise (controls) were invited to one visit and assessed with performance-based test, blood-sampling and self-reported questionnaires. Forty-seven out of 70 older adults accepted participation, 24 from the exercise group and 23 from the control group. Comparisons of the result with baseline values were performed and explanatory factors for increase of physical activity were examined with logistic regression. RESULTS: The result show that there was no significant difference in weekly hours of physical activity when groups where compared. However, participants in the exercise group rated significantly increased weekly hours of physical activity after four years (p = 0.004) when compared to baseline. Higher levels of fatigue, BMI and physical activity, at baseline were negatively associated with increased physical activity after four years. There was no significant difference in change of physical fitness between the groups. Within group analysis showed that the control group reported increased pain (p = 0.035), fatigue (p = 0.023) increased number of tender joints (p = 0.028) higher disease activity (p = 0.007) and worsening of global health (p = 0.004) when compared to baseline while the exercise group remained at the same level as at baseline. CONCLUSION: These results indicate that introducing moderate- to high intensity exercise with person-centred guidance might favor increased physical activity after four years in older adults with RA. Previous partaking in moderate- to high intensity exercise might also be protective against increased disease activity, pain and fatigue over time.

6.
Immun Ageing ; 17: 12, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32467712

RESUMO

OBJECTIVE: Exercise can improve immune health and is beneficial for physical function in patients with rheumatoid arthritis (RA), but the immunological mechanisms are largely unknown. We evaluated the effect of moderate- to high intensity exercise with person-centred guidance on cells of the immune system, with focus on regulatory cell populations, in older adults with RA. METHODS: Older adults (≥65 years) with RA were randomized to either 20-weeks of moderate - to high intensity aerobic and resistance exercise (n = 24) or to an active control group performing home-based exercise of light intensity (n = 25). Aerobic capacity, muscle strength, DAS28 and CRP were evaluated. Blood samples were collected at baseline and after 20 weeks. The frequency of immune cells defined as adaptive regulatory populations, CD4 + Foxp3 + CD25 + CD127- T regulatory cells (Tregs) and CD19 + CD24hiCD38hi B regulatory cells (Bregs) as well as HLA-DR-/lowCD33 + CD11b + myeloid derived suppressor cells (MDSCs), were assessed using flow cytometry. RESULTS: After 20 weeks of moderate- to high intensity exercise, aerobic capacity and muscle strength were significantly improved but there were no significant changes in Disease Activity Score 28 (DAS28) or CRP. The frequency of Tregs and Bregs decreased significantly in the intervention group, but not in the active control group. The exercise intervention had no effect on MDSCs. The reduction in regulatory T cells in the intervention group was most pronounced in the female patients. CONCLUSION: Moderate- to high intensity exercise in older adults with RA led to a decreased proportion of Tregs and Bregs, but that was not associated with increased disease activity or increased inflammation. TRIAL REGISTRATION: Improved Ability to Cope With Everyday Life Through a Person-centered Training Program in Elderly Patients With Rheumatoid Arthritis - PEP-walk Study, NCT02397798. Registered at ClinicalTrials.gov March 19, 2015.

7.
J Chem Ecol ; 46(3): 344-360, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32002720

RESUMO

The vast spectrum of inducible plant defenses can have direct negative effects on herbivores, or indirect effects, for instance in the form of herbivore-induced plant volatiles (HIPVs) that attract natural enemies. Various arthropods have evolved ways to suppress plant defenses. To test whether this is the case for caterpillar-induced HIPVs, we compared the volatile induction by Spodoptera frugiperda (Lepidoptera: Noctuidae), which is particularly well adapted to feed on maize (Zea mays), with the induction by three more generalist noctuid larvae. We tested the hypothesis that S. frugiperda suppresses HIPV emissions in maize, and thereby reduces attractiveness to natural enemies. HIPV emissions triggered by S. frugiperda when feeding on maize were indeed found to be significantly weaker than by Spodoptera littoralis, Spodoptera exigua, and Helicoverpa armigera. The suppression seems specific for maize, as we found no evidence for this when S. frugiperda caterpillars fed on cotton (Gossypium herbaceum). Artificially damaged maize plants treated with larval regurgitant revealed that HIPV suppression may be related to factors in the caterpillars' oral secretions. We also found evidence that differential physical damage that the caterpillars inflict on maize leaves may play a role. The suppressed induction of HIPVs had no apparent consequences for the attraction of a common parasitoid of S. frugiperda, Cotesia marginiventris (Hymenoptera: Braconidae). Nevertheless, the ability to manipulate the defenses of its main host plant may have contributed to the success of S. frugiperda as a major pest of maize, especially in Africa and Asia, which it has recently invaded.


Assuntos
Herbivoria , Mariposas/fisiologia , Folhas de Planta/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Zea mays/metabolismo , Animais , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Especificidade da Espécie , Spodoptera/crescimento & desenvolvimento , Spodoptera/fisiologia
8.
J Econ Entomol ; 113(1): 1-25, 2020 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-31811713

RESUMO

Arthropod pest outbreaks are unpredictable and not uniformly distributed within fields. Early outbreak detection and treatment application are inherent to effective pest management, allowing management decisions to be implemented before pests are well-established and crop losses accrue. Pest monitoring is time-consuming and may be hampered by lack of reliable or cost-effective sampling techniques. Thus, we argue that an important research challenge associated with enhanced sustainability of pest management in modern agriculture is developing and promoting improved crop monitoring procedures. Biotic stress, such as herbivory by arthropod pests, elicits physiological defense responses in plants, leading to changes in leaf reflectance. Advanced imaging technologies can detect such changes, and can, therefore, be used as noninvasive crop monitoring methods. Furthermore, novel methods of treatment precision application are required. Both sensing and actuation technologies can be mounted on equipment moving through fields (e.g., irrigation equipment), on (un)manned driving vehicles, and on small drones. In this review, we focus specifically on use of small unmanned aerial robots, or small drones, in agricultural systems. Acquired and processed canopy reflectance data obtained with sensing drones could potentially be transmitted as a digital map to guide a second type of drone, actuation drones, to deliver solutions to the identified pest hotspots, such as precision releases of natural enemies and/or precision-sprays of pesticides. We emphasize how sustainable pest management in 21st-century agriculture will depend heavily on novel technologies, and how this trend will lead to a growing need for multi-disciplinary research collaborations between agronomists, ecologists, software programmers, and engineers.


Assuntos
Artrópodes , Praguicidas , Agricultura , Animais , Controle de Pragas , Plantas
9.
Rheumatol Int ; 39(9): 1585-1594, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31327051

RESUMO

Fatigue is described as a dominant and disturbing symptom of rheumatoid arthritis (RA) regardless of the advances in pharmacological treatment. Fatigue is also found to correlate with depression. The objective was to evaluate the impact of moderate-to-high intensity, aerobic and resistance exercise with person-centered guidance on fatigue, anxiety and depression, in older adults with RA. Comparisons were made between older adults (> 65 years) with RA taking part in a 20-week moderate-to-high intensity exercise at a gym (n = 36) or in home-based exercise of light intensity (n = 38). Assessments were performed at baseline, at 20 weeks, and at 52 weeks. Outcomes were differences in Multidimensional Fatigue Inventory (MFI-20), Visual Analog Scale Fatigue (VAS fatigue), and Hospital Anxiety and Depression Scale (HADS). Analysis of metabolomics was also performed. The subscales "physical fatigue" and "mental fatigue" in MFI-20 and symptoms of depression using HADS depression scale improved significantly at week 20 in the exercise group compared with the control group. Exercise did not influence global fatigue rated by VAS or subscales "reduced motivation", "reduced activity" and "general fatigue" in MFI-20. No significant change was found on the anxiety index of HADS. The improvements in physical fatigue were associated with changes in the metabolism of lipids, bile acids, the urea cycle and several sugars. Moderate-to-high intensity exercise with person-centered guidance decreased fatigue and improved symptoms of depression and were accompanied by metabolic changes in older adults with RA.


Assuntos
Artrite Reumatoide/terapia , Depressão/terapia , Terapia por Exercício/métodos , Tolerância ao Exercício , Fadiga/terapia , Serviços de Assistência Domiciliar , Assistência Centrada no Paciente/métodos , Idoso , Artrite Reumatoide/sangue , Artrite Reumatoide/fisiopatologia , Artrite Reumatoide/psicologia , Biomarcadores/sangue , Depressão/sangue , Depressão/fisiopatologia , Depressão/psicologia , Metabolismo Energético , Terapia por Exercício/efeitos adversos , Fadiga/sangue , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Nível de Saúde , Humanos , Masculino , Saúde Mental , Recuperação de Função Fisiológica , Suécia , Fatores de Tempo , Resultado do Tratamento
10.
Plant Signal Behav ; 14(8): 1616517, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31131703

RESUMO

Nutrient availability impacts plant indirect defenses, such as emissions of herbivore-induced plant volatiles (HIPVs) that attract natural enemies of herbivores. However, the effects are variable depending on the cropping system, and emissions may increase, decrease, or be not affected by nutrient availability. Here, we evaluated the effects of different fertilizer regimes, which varied nitrogen (N), phosphorus (P), and potassium (K) availability, on HIPV emissions in cranberry, Vaccinium macrocarpon Ait. Plants included six cranberry varieties that were subjected to four different fertilizer regimes and either noninduced or induced with methyl jasmonate (MeJA), an elicitor of HIPVs, in a 6 × 4 × 2 factorial design. Results show that enhanced NPK fertilizer applications increased total HIPV emissions in MeJA-treated cranberries, regardless of variety. This effect was due to an increase in plant fresh weight. Although the ecological effects of increased HIPV emissions need to be investigated, these findings may have implications for natural enemy manipulation in agro-ecosystems.


Assuntos
Vaccinium macrocarpon/metabolismo , Acetatos/farmacologia , Ciclopentanos/farmacologia , Fertilizantes , Genótipo , Oxilipinas/farmacologia , Vaccinium macrocarpon/efeitos dos fármacos
11.
Artigo em Inglês | MEDLINE | ID: mdl-30988827

RESUMO

BACKGROUND: Besides being health enhancing and disease preventing, exercise is also an important part of the management of chronic conditions, including the inflammatory joint disease rheumatoid arthritis (RA). However, older adults with RA present a lower level of physical activity than healthy older adults. The aim of this qualitative study was to explore aspects of participation in moderate- to high-intensity exercise with person-centred guidance influencing the transition to independent exercise for older adults with RA. METHODS: A qualitative interview study was conducted. In-depth interviews with 16 adults with RA aged between 68 and 75 years, who had taken part in the intervention arm of a randomized controlled trial performing moderate- to- high-intensity exercise with person-centred guidance, were analysed using qualitative content analysis. RESULTS: The analysis resulted in six main categories: A feasible opportunity to adopt exercise, Experiencing positive effects of exercise, Contextual factors affect the experience of exercise, Developing knowledge and thinking, Finding one's way, and Managing barriers for exercise. The exercise with person-centred guidance was described as a feasible opportunity to start exercising as a basis for the transition to independent exercise. They described developing knowledge and thinking about exercise during the intervention enabling them to manage the transition to independent exercise. Finding one's own way for exercise became important for sustaining independent exercise. Lastly, barriers for exercise and strategies for overcoming these were described. Reduced physical health, both temporary and permanent, was described as a considerable barrier for exercise. CONCLUSION: The participants described several aspects of participating in exercise that influenced and facilitated their transition to independent exercise. The exercise was experienced as manageable and positive, by a careful introduction and development of an individual exercise routine in partnership with a physiotherapist. This seems to have favored the development of self-efficacy, with importance for future independent exercise. Reduced physical health, both temporary and permanent, was described as a considerable barrier for exercise. The personal process of trying to make the exercise one's own, and developing knowledge about exercise and new thoughts about oneself, seemed to prepare the participants for managing independent exercise and overcoming barriers.

12.
J Chem Ecol ; 45(3): 298-312, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30607684

RESUMO

Herbivorous insects are important problems in cranberry (Vaccinium macrocarpon Ait.) production. The use of chemical pesticides is common practice, but beneficial insects such as natural enemies of herbivores (e.g. predators and parasitoids) could be affected as well. Therefore, we studied the defensive mechanisms that cranberry plants use to combat pests, focusing on herbivore-induced plant volatiles (HIPVs), which can be used to recruit predators and parasitoids foraging for prey or hosts. Then, we used synthetic HIPVs to test the attraction of natural enemies. In a greenhouse, we assessed nine cranberry genotypes for expression of genes involved in HIPV biosynthesis and/or emission of HIPVs. In an experimental field, we assessed whether baiting traps with individual or combinations of HIPVs increased attractiveness to natural enemies. The results showed that different cranberry genotypes vary in their emission of monoterpenes and sesquiterpenes but not in their expression of two genes associated with terpene biosynthesis, α-humulene/ß-caryophyllene synthase and (3S,6E)-nerolidol/R-linalool synthase. Induction with methyl jasmonate or herbivore (gypsy moth, Lymantria dispar L.) feeding increased the expression of these genes and emission of HIPVs. The HIPV methyl salicylate (MeSA), alone or in combination with other HIPVs, increased syrphid attraction by 6-fold in the field, while (Z)-3-hexenyl acetate and MeSA repelled ladybeetles and megaspilids, respectively. Linalool and ß-caryophyllene elicited no behavioral responses of natural enemies. Elucidating the mechanisms of pest resistance, as well as experimentally augmenting plant defenses such as HIPVs, may contribute to the development of more sustainable pest management practices in crops, including cranberries.


Assuntos
Expressão Gênica , Genótipo , Herbivoria , Fenótipo , Vaccinium macrocarpon/metabolismo , Compostos Orgânicos Voláteis/metabolismo
13.
Arthritis Care Res (Hoboken) ; 71(1): 61-70, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29696812

RESUMO

OBJECTIVE: To evaluate the effect of a moderate-to-high-intensity, aerobic and resistance exercise with person-centered guidance in older adults with rheumatoid arthritis (RA), through a randomized controlled multicenter trial. METHODS: Older adults (ages 65-75 years) with RA (n = 74) were randomized to either a 20-week exercise intervention at a gym (n = 36) or to home-based exercise of light intensity (n = 38). Assessments were performed at baseline, at 20 weeks, and at 12 months. The primary outcome was the difference in the Health Assessment Questionnaire disability index (HAQ DI) score, and the secondary outcomes were the differences in physical fitness assessed by a cardiopulmonary exercise test, an endurance test, the timed up and go test, the sit to stand test, and an isometric elbow flexion force measurement. RESULTS: No significant differences between the groups were found for the primary outcome, HAQ DI score. Within the intervention group there was a significant improvement in the HAQ DI score when compared to baseline (P = 0.022). Aerobic capacity (P < 0.001) and 3 of 4 additional performance-based tests of endurance and strength significantly improved (P < 0.05) in the intervention group when compared to the control group. In the intervention group, 71% of patients rated their health as much or very much improved compared to 24% of patients in the control group (P < 0.001). At the 12-month follow-up, there were no significant differences in change between the 2 groups on the HAQ DI score. A significant between-group difference was found for change in an endurance test (P = 0.022). CONCLUSION: Aerobic and resistance exercise with person-centered guidance improved physical fitness in terms of aerobic capacity, endurance, and strength in older adults with RA.


Assuntos
Artrite Reumatoide/epidemiologia , Artrite Reumatoide/terapia , Exercício Físico/fisiologia , Treinamento Resistido/métodos , Idoso , Artrite Reumatoide/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Treinamento Resistido/tendências , Inquéritos e Questionários , Suécia/epidemiologia , Resultado do Tratamento
14.
Plant Cell Environ ; 34(7): 1088-103, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21410707

RESUMO

Determining links between plant defence strategies is important to understand plant evolution and to optimize crop breeding strategies. Although several examples of synergies and trade-offs between defence traits are known for plants that are under attack by multiple organisms, few studies have attempted to measure correlations of defensive strategies using specific single attackers. Such links are hard to detect in natural populations because they are inherently confounded by the evolutionary history of different ecotypes. We therefore used a range of 20 maize inbred lines with considerable differences in resistance traits to determine if correlations exist between leaf and root resistance against pathogens and insects. Aboveground resistance against insects was positively correlated with the plant's capacity to produce volatiles in response to insect attack. Resistance to herbivores and resistance to a pathogen, on the other hand, were negatively correlated. Our results also give first insights into the intraspecific variability of root volatiles release in maize and its positive correlation with leaf volatile production. We show that the breeding history of the different genotypes (dent versus flint) has influenced several defensive parameters. Taken together, our study demonstrates the importance of genetically determined synergies and trade-offs for plant resistance against insects and pathogens.


Assuntos
Imunidade Inata , Folhas de Planta/química , Raízes de Plantas/química , Zea mays/genética , Animais , Ascomicetos/patogenicidade , Biomassa , Besouros/crescimento & desenvolvimento , Besouros/patogenicidade , Colletotrichum/patogenicidade , Comportamento Alimentar , Ligação Genética , Genótipo , Proteínas de Fluorescência Verde , Larva/crescimento & desenvolvimento , Larva/patogenicidade , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Spodoptera/crescimento & desenvolvimento , Spodoptera/patogenicidade , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Zea mays/imunologia , Zea mays/microbiologia , Zea mays/parasitologia
15.
Planta ; 232(6): 1423-32, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20839007

RESUMO

Jasmonates (JAs) and salicylic acid (SA) are plant hormones that play pivotal roles in the regulation of induced defenses against microbial pathogens and insect herbivores. Their signaling pathways cross-communicate providing the plant with a regulatory potential to finely tune its defense response to the attacker(s) encountered. In Arabidopsis thaliana, SA strongly antagonizes the jasmonic acid (JA) signaling pathway, resulting in the downregulation of a large set of JA-responsive genes, including the marker genes PDF1.2 and VSP2. Induction of JA-responsive marker gene expression by different JA derivatives was equally sensitive to SA-mediated suppression. Activation of genes encoding key enzymes in the JA biosynthesis pathway, such as LOX2, AOS, AOC2, and OPR3 was also repressed by SA, suggesting that the JA biosynthesis pathway may be a target for SA-mediated antagonism. To test this, we made use of the mutant aos/dde2, which is completely blocked in its ability to produce JAs because of a mutation in the ALLENE OXIDE SYNTHASE gene. Mutant aos/dde2 plants did not express the JA-responsive marker genes PDF1.2 or VSP2 in response to infection with the necrotrophic fungus Alternaria brassicicola or the herbivorous insect Pieris rapae. Bypassing JA biosynthesis by exogenous application of methyl jasmonate (MeJA) rescued this JA-responsive phenotype in aos/dde2. Application of SA suppressed MeJA-induced PDF1.2 expression to the same level in the aos/dde2 mutant as in wild-type Col-0 plants, indicating that SA-mediated suppression of JA-responsive gene expression is targeted at a position downstream of the JA biosynthesis pathway.


Assuntos
Arabidopsis/genética , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Ácido Salicílico/metabolismo , Sequência de Bases , Northern Blotting , Primers do DNA , Genes de Plantas , Mutação , Reação em Cadeia da Polimerase , Transdução de Sinais
16.
Plant J ; 59(2): 292-302, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19392694

RESUMO

Plants activate local and systemic defence mechanisms upon exposure to stress. This innate immune response is partially regulated by plant hormones, and involves the accumulation of defensive metabolites. Although local defence reactions to herbivores are well studied, less is known about the impact of root herbivory on shoot defence. Here, we examined the effects of belowground infestation by the western corn rootworm Diabrotica virgifera virgifera on aboveground resistance in maize. Belowground herbivory by D. v. virgifera induced aboveground resistance against the generalist herbivore Spodoptera littoralis, and the necrotrophic pathogen Setosphaeria turcica. Furthermore, D. v. virgifera increased shoot levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and primed the induction of chlorogenic acid upon subsequent infestation by S. littoralis. To gain insight into the signalling network behind this below- and aboveground defence interaction, we compiled a set of 32 defence-related genes, which can be used as transcriptional marker systems to detect activities of different hormone-response pathways. Belowground attack by D. v. virgifera triggered an ABA-inducible transcription pattern in the shoot. The quantification of defence hormones showed a local increase in the production of oxylipins after root and shoot infestation by D. v. virgifera and S. littoralis, respectively. On the other hand, ABA accumulated locally and systemically upon belowground attack by D. v. virgifera. Furthermore, D. v. virgifera reduced the aboveground water content, whereas the removal of similar quantities of root biomass had no effect. Our study shows that root herbivory by D. v. virgifera specifically alters the aboveground defence status of a maize, and suggests that ABA plays a role in the signalling network mediating this interaction.


Assuntos
Benzoxazinas/metabolismo , Besouros/fisiologia , Raízes de Plantas/metabolismo , Zea mays/metabolismo , Ácido Abscísico/metabolismo , Animais , Ascomicetos/fisiologia , Ácido Clorogênico/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Larva/fisiologia , Mariposas/fisiologia , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , RNA de Plantas/metabolismo , Transdução de Sinais , Zea mays/genética , Zea mays/fisiologia
17.
Plant Physiol ; 149(4): 1797-809, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19176718

RESUMO

The plant hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) play crucial roles in the signaling network that regulates induced defense responses against biotic stresses. Antagonism between SA and JA operates as a mechanism to fine-tune defenses that are activated in response to multiple attackers. In Arabidopsis (Arabidopsis thaliana), NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) was demonstrated to be required for SA-mediated suppression of JA-dependent defenses. Because ET is known to enhance SA/NPR1-dependent defense responses, we investigated the role of ET in the SA-JA signal interaction. Pharmacological experiments with gaseous ET and the ET precursor 1-aminocyclopropane-1-carboxylic acid showed that ET potentiated SA/NPR1-dependent PATHOGENESIS-RELATED1 transcription, while it rendered the antagonistic effect of SA on methyl jasmonate-induced PDF1.2 and VSP2 expression NPR1 independent. This overriding effect of ET on NPR1 function in SA-JA cross talk was absent in the npr1-1/ein2-1 double mutant, demonstrating that it is mediated via ET signaling. Abiotic and biotic induction of the ET response similarly abolished the NPR1 dependency of the SA-JA signal interaction. Furthermore, JA-dependent resistance against biotic attackers was antagonized by SA in an NPR1-dependent fashion only when the plant-attacker combination did not result in the production of high levels of endogenous ET. Hence, the interaction between ET and NPR1 plays an important modulating role in the fine tuning of the defense signaling network that is activated upon pathogen and insect attack. Our results suggest a model in which ET modulates the NPR1 dependency of SA-JA antagonism, possibly to compensate for enhanced allocation of NPR1 to function in SA-dependent activation of PR genes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Etilenos/metabolismo , Oxilipinas/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais , Acetatos/farmacologia , Aminoácidos Cíclicos/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Modelos Biológicos , Oxilipinas/farmacologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/efeitos dos fármacos
18.
Antonie Van Leeuwenhoek ; 93(4): 407-13, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18183497

RESUMO

A novel cold-tolerant fungus, Fibulorhizoctonia psychrophila, was isolated from a refrigerated carrot storage facility and identified as an anamorph of Athelia, often classified in Rhizoctonia s.l. Growth of this fungus was observed between 0 and 20 degrees C with an optimum at 9-12 degrees C, while incubation of mycelium grown at 15-32 degrees C resulted in absence of growth even after the fungus was transferred back to 15 degrees C. Growth was inhibited in the presence of the antifungals sorbic acid or natamycin, in particular when the fungus was incubated at 18 degrees C. F. psychrophila produces polysaccharide degrading enzymes that, when compared to enzymes from the ascomycete fungus Aspergillus niger, retain a larger proportion of their activity at lower temperatures. This indicates that F. psychrophila could be used as a source for novel industrial enzymes that are active at 4-15 degrees C.


Assuntos
Basidiomycota/isolamento & purificação , Daucus carota/microbiologia , Antifúngicos/farmacologia , Basidiomycota/efeitos dos fármacos , Basidiomycota/genética , Basidiomycota/crescimento & desenvolvimento , Temperatura Baixa , DNA Fúngico/genética , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Enzimas/metabolismo , Dados de Sequência Molecular , Polissacarídeos/metabolismo , RNA Ribossômico 5,8S/genética
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