RESUMO
Many plants associate with arbuscular mycorrhizal fungi for nutrient acquisition, while legumes also associate with nitrogen-fixing rhizobial bacteria. Both associations rely on symbiosis signaling and here we show that cereals can perceive lipochitooligosaccharides (LCOs) for activation of symbiosis signaling, surprisingly including Nod factors produced by nitrogen-fixing bacteria. However, legumes show stringent perception of specifically decorated LCOs, that is absent in cereals. LCO perception in plants is activated by nutrient starvation, through transcriptional regulation of Nodulation Signaling Pathway (NSP)1 and NSP2. These transcription factors induce expression of an LCO receptor and act through the control of strigolactone biosynthesis and the karrikin-like receptor DWARF14-LIKE. We conclude that LCO production and perception is coordinately regulated by nutrient starvation to promote engagement with mycorrhizal fungi. Our work has implications for the use of both mycorrhizal and rhizobial associations for sustainable productivity in cereals.
Assuntos
Medicago truncatula , Micorrizas , Rhizobium , Medicago truncatula/microbiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Micorrizas/fisiologia , Simbiose , Rhizobium/metabolismo , NutrientesRESUMO
The growth and development of root systems is influenced by mechanical properties of the substrate in which the plants grow. Mechanical impedance, such as by compacted soil, can reduce root elongation and limit crop productivity. To understand better the mechanisms involved in plant root responses to mechanical impedance stress, we investigated changes in the root transcriptome and hormone signalling responses of Arabidopsis to artificial root barrier systems in vitro. We demonstrate that upon encountering a barrier, reduced Arabidopsis root growth and a characteristic 'step-like' growth pattern is due to a reduction in cell elongation associated with changes in signalling gene expression. Data from RNA-sequencing combined with reporter line and mutant studies identified essential roles for reactive oxygen species, ethylene and auxin signalling during the barrier response. We propose a model in which early responses to mechanical impedance include reactive oxygen signalling integrated with ethylene and auxin responses to mediate root growth changes. Inhibition of ethylene responses allows improved growth in response to root impedance, an observation that may inform future crop breeding programmes.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Impedância Elétrica , Etilenos , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Melhoramento Vegetal , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVE: To identify the progression of non-nutritive sucking (NNS) across postmenstrual age (PMA) and to investigate the relationship of NNS with medical and social factors and oral feeding. STUDY DESIGN: Fifty preterm infants born at ≤32 weeks gestation had NNS assessed weekly starting at 32 weeks PMA with the NTrainer System. Oral feeding was assessed at 38 weeks PMA. RESULTS: There were increases in NNS bursts per minute (p = 0.005), NNS per minute (p < 0.0001), NNS per burst (p < 0.001), and peak pressure (p = 0.0003) with advancing PMA. Level of immaturity and medical complications were related to NNS measures (p < 0.05). NNS measures were not related to Neonatal Oral Motor Assessment Scale scores. Smaller weekly change in NNS peak pressure (p = 0.03; ß = -1.4) was related to feeding success at 38 weeks PMA. CONCLUSION: Infants demonstrated NNS early in gestation. Variability in NNS scores could reflect medical complications and immaturity. More stable sucking pressure across time was related to feeding success at 38 weeks PMA.
Assuntos
Recém-Nascido Prematuro/fisiologia , Comportamento de Sucção/fisiologia , Fatores Etários , Métodos de Alimentação , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro/psicologia , Masculino , Estudos ProspectivosRESUMO
The current report describes 3 studies conducted to develop 8-item child- and parent-report measures to further the understanding of the role of behavioral avoidance in the development, maintenance, and treatment of childhood anxiety disorders. Participants included both clinical (N=463; ages 8 to 12) and community (N=421; ages 7 to 18) samples of children and their parents from primarily Caucasian intact families. Follow-up data were collected from 104 families in the community sample. Overall, the measures were internally consistent and related to anxiety, distress, and alternative measures of avoidance in both samples. Parent report of children's behavioral avoidance evidenced the strongest psychometric properties, differentiated among clinical and community populations, and most importantly, predicted children's anxiety at least 8 months later over and above initial anxiety ratings. Moreover, decreases in avoidance were associated with successful exposure therapy. These results are consistent with the role of behavioral avoidance in the development of anxiety and provide an efficient tool for assessing the role of avoidance in clinical and research settings.
Assuntos
Transtornos de Ansiedade/psicologia , Comportamento Infantil/psicologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pais , Psicometria , Autorrelato , Inquéritos e QuestionáriosRESUMO
The present study examines treatment length and timing of exposure from two child anxiety disorders clinics. Data regarding symptoms and treatment characteristics for 28 youth were prospectively obtained through self, parent, and therapist report at each session. Information regarding length of treatment, timing of exposure initiation, and drop-out rates were compared with those obtained through efficacy and effectiveness trials of manualized treatment for anxious youth. Findings from the authors' clinical data revealed significantly shorter treatment duration with exposures implemented sooner than in the previous studies. Dropout rates were significantly higher than in the efficacy trial but comparable with the effectiveness trial. Outcome data from a subset of eight patients revealed large effect sizes. These findings suggest that effective treatment can be shorter and more focused on exposure than is often outlined in manuals and have important implications for outcome research and dissemination.
Assuntos
Transtornos de Ansiedade/terapia , Terapia Implosiva/métodos , Adolescente , Criança , Feminino , Humanos , Masculino , Manuais como Assunto , Pacientes Desistentes do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Resultado do TratamentoRESUMO
The present study examines treatment length and timing of exposure from two child anxiety disorders clinics. Data regarding symptoms and treatment characteristics for 28 youth were prospectively obtained through self, parent, and therapist report at each session. Information regarding length of treatment, timing of exposure initiation, and drop-out rates were compared with those obtained through efficacy and effectiveness trials of manualized treatment for anxious youth. Findings from the authors' clinical data revealed significantly shorter treatment duration with exposures implemented sooner than in the previous studies. Dropout rates were significantly higher than in the efficacy trial but comparable with the effectiveness trial. Outcome data from a subset of eight patients revealed large effect sizes. These findings suggest that effective treatment can be shorter and more focused on exposure than is often outlined in manuals and have important implications for outcome research and dissemination.
Assuntos
Transtornos de Ansiedade/terapia , Terapia Implosiva , Adolescente , Transtornos de Ansiedade/diagnóstico , Criança , Feminino , Humanos , Masculino , Pacientes Desistentes do Tratamento , Estudos Prospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Abstract The current study examined specific emotional, behavioral, and cognitive variables that may distinguish obsessive-compulsive disorder (OCD) from generalized anxiety disorder (GAD), social phobia (SoP), and separation anxiety disorder (SAD) in youth. Youth with OCD (n=26) and other anxiety disorders (ADs; n=31), aged 7-12 years (56.1% males), and their parents participated. The study compared the two anxious groups on levels of emotional, behavioral, and cognitive functioning, as well as impairment associated with the disorder. Results indicated that in comparison to youth with GAD, SoP, or SAD, youth with OCD were found to have poorer emotion regulation skills, as well as greater oppositionality, cognitive problems/inattention, and parent impairment associated with the disorder. The findings suggest that there are unique characteristics of OCD that may differentiate this disorder from other ADs in youth. Potential clinical implications and directions for future research are discussed.
Assuntos
Transtornos de Ansiedade/psicologia , Cognição , Emoções , Transtorno Obsessivo-Compulsivo/psicologia , Ansiedade de Separação/psicologia , Criança , Comportamento Infantil/psicologia , Inteligência Emocional , Feminino , Humanos , Masculino , Transtornos Fóbicos/psicologia , Escalas de Graduação Psiquiátrica , Testes PsicológicosRESUMO
The current study sought to provide practical information for the clinical use of child and parent reports of child anxiety symptoms by investigating agreement between parent, child, and clinician as well as the predictive value of this information. Examining 88 anxious children and their parents, the study compared agreement by correlating parent and child responses on the Spence Children's Anxiety Scale (SCAS); comparing parent and child responses to clinician data operationalized through continuous and dichotomous variables from the Anxiety Disorder Interview Schedule for Children; and examining the relative clinical utility of parent and child reports on the SCAS in terms of positive and negative predictive value. Results indicated that parent and child agreement on the SCAS was moderate to high for most anxiety disorder symptoms and that both were generally consistent with clinician impressions. Moreover, both child and parent provided unique information to the diagnostic process.
Assuntos
Transtornos de Ansiedade/diagnóstico , Ansiedade/diagnóstico , Psiquiatria Infantil , Valor Preditivo dos Testes , Psicometria , Autorrelato , Adolescente , Fatores Etários , Ansiedade/psicologia , Transtornos de Ansiedade/psicologia , Distribuição de Qui-Quadrado , Criança , Feminino , Humanos , Modelos Logísticos , Masculino , Análise Multivariada , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estatística como Assunto , Inquéritos e QuestionáriosRESUMO
This study examined the feasibility of a 5-day intensive treatment for pediatric obsessive-compulsive disorder (OCD). Fifteen children with OCD received a week-long treatment based on exposure and response prevention (ERP). The intervention also emphasized teaching children and parents how to conduct ERP independently at home. All families completed the week-long treatment and symptoms improved significantly as measured by self- and parent-report forms, as well as the Children's Yale-Brown Obsessive-Compulsive Scale, F(2, 22)=45.67, p<.05. Total CY-BOCS scores decreased significantly from pretreatment (M=28.00, SD=4.24) to posttreatment [M=16.00, SD=6.0, F(1, 11)=34.38, p<.05] and from posttreatment to 5-month follow-up [M=11.5, SD=7.3; F(1, 11)=12.94, p<.05]. This level of improvement was consistent with other intensive treatments for pediatric OCD. The study suggests that the 5-day program is a promising treatment for children with OCD who do not have access to local providers.