Transcriptional and Chemical Changes in Soybean Leaves in Response to Long-Term Aphid Colonization

Soybean aphids (Aphis glycines Matsumura) are specialized insects that feed on soybean (Glycine max) phloem sap. Transcriptome analyses have shown that resistant soybean plants mount a fast response that limits aphid feeding and population growth. Conversely, defense responses in susceptible plants are slower and it is hypothesized that aphids block effective defenses in the compatible interaction. Unlike other pests, aphids can colonize plants for long periods of time; yet the effect on the plant transcriptome after long-term aphid feeding has not been analyzed for any plant–aphid interaction. We analyzed the susceptible and resistant (Rag1) transcriptome response to aphid feeding in soybean plants colonized by aphids (biotype 1) for 21 days. We found a reduced resistant response and a low level of aphid growth on Rag1 plants, while susceptible plants showed a strong response consistent with pattern-triggered immunity. GO-term analyses identified chitin regulation as one of the most overrepresented classes of genes, suggesting that chitin could be one of the hemipteran-associated molecular pattern that triggers this defense response. Transcriptome analyses also indicated the phenylpropanoid pathway, specifically isoflavonoid biosynthesis, was induced in susceptible plants in response to long-term aphid feeding. Metabolite analyses corroborated this finding. Aphid-treated susceptible plants accumulated daidzein, formononetin, and genistein, although glyceollins were present at low levels in these plants. Choice experiments indicated that daidzein may have a deterrent effect on aphid feeding. Mass spectrometry imaging showed these isoflavones accumulate likely in the mesophyll cells or epidermis and are absent from the vasculature, suggesting that isoflavones are part of a non-phloem defense response that can reduce aphid feeding. While it is likely that aphid can initially block defense responses in compatible interactions, it appears that susceptible soybean plants can eventually mount an effective defense in response to long-term soybean aphid colonization

An examination of intentions of recommending fitness centers by user members

The goal of this study was to examine what experiences members have with fitness centers that influence their intentions for recommendation. After item generation and content validity, as well as a pilot test, a survey was conducted among members of five different clubs (n=1750). The questionnaire included measures of service quality attributes, accessibility, well-being in life, well-being in a club, and intentions to recommend a fitness center. Results using a structural equation model provide evidence that only service quality attributes and well-being in a club have positive effect on intentions of users to recommend it. Well-being in life has a negative effect on the intentions for recommendation, while accessibility shows no predictive effect. These findings suggest implications for the management of a club, such as the need to create a pleasant environment and to provide a personalized service directed towards the members’ goals in order to improve well-being in a club and contribute to increase the intentions to recommend the fitness centers to others.O objetivo deste estudo foi examinar como as experiências de usuários de centros de atividade física interferem nas intenções em recomendar serviços. Depois de gerar itens e validar o conteúdo, aplicou-se um pré-teste, o questionário final foi aplicado a sócios de cinco clubes de fitness (n=1.750). O questionário incluiu atributos da qualidade do serviço, acessibilidade, bem-estar na vida, bem-estar no clube e intenção de recomendar. O modelo de equações estruturais mostrou que apenas os atributos da qualidade do serviço e bem-estar no clube têm um efeito positivo sobre as intenções de recomendar. O bem-estar na vida tem um efeito negativo sobre as intenções para recomendar, enquanto que a acessibilidade não mostra nenhum efeito preditivo. Estas conclusões sugerem a necessidade de criar um ambiente agradável nos clubes e de oferecer um serviço personalizado para os objetivos dos sócios, a fim de melhorar o bem-estar no clube e contribuir para a intenção de recomendar o ginásio. Palavras-chave: intenção de recomendar, atributos da qualSin financiación0.191 SJR (2014) Q3, posición 172/231 Health (social science), 1027/1811 Medicine (miscellaneous); Q4, 112/128 Sports scienceUE