1,924 research outputs found

    Tomato quality in different postharvest phases

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    Manual classification using wooden boxes (K) are still very common in Brazil. The main goal of this work was to characterize tomatoes of the cultivar Débora type, for maturity index, diameter and external defects at harvest time and at Retail Market, CEASA, Campinas, São Paulo State, Brazil. This research also evaluated parameters related to mechanical injury (%), weight loss (%) and quality during the main phases (1) harvest; (2) before field sorting and classification; (3) after field sorting and packaging in K boxes; (4) at CEASA. 120 fruits were taken at each stage. Defects and physical damage were evaluated using a score scale. Fruits sampled in the field showed external damages, due to bruising from bamboo stakes, insects attack and physiological and nutritional disorders. Fruits were harvested mainly at green maturity stage (48%). But, when sampled at CEASA this amount dropped to 26,3%, having mixed diameters fruits, 55,4% at 50-60mm and 43,9% over 60 mm. The results showed an increase in mechanical injury (%), weight loss (%) and loss of quality during the stages. Fruits taken directly from field showed better quality (45%) after storage for 21 days than fruits sampled at terminal market, CEASA (5,8%).A classificação manual para tomate de mesa e a utilização da caixa K para transporte ainda predomina em diversas regiões no Brasil. O presente trabalho buscou caracterizar frutos da cultivar Débora provenientes de plantios comerciais quanto ao estádio de maturidade, diâmetro e defeitos físicos e danos na etapa de colheita e no recebimento do produto na CEASA, de Campinas. Objetivou-se também avaliar a incidência de danos físicos, a perda de peso e alterações na qualidade em frutos retirados diretamente no campo de produção e nas etapas da colheita (1), recebimento em um barracão para classificação manual (2), após classificação manual e embalagem (3) e na comercialização do produto na CEASA (4). Para está amostragem retirou-se 120 frutos em cada etapa. Defeitos e danos físicos presentes foram analisados utilizando-se uma escala de notas. Frutos amostrados em campo já demonstravam danos físicos, provenientes principalmente da abrasão com as estacas de bambu e fios de amarrio, ataque de insetos e distúrbios fisiológicos e nutricionais. Os frutos foram colhidos predominantemente no estádio de maturação verde-maduro (48%). Na amostragem retirada na CEASA dois dias após a colheita está porcentagem era de 26,3%, com misturas de diâmetros, sendo que 55,4% dos frutos encontravam-se entre 50-60 mm e 43,9% acima de 60 mm. Observou-se um incremento nos danos físicos e na perda de peso e conseqüente perda na qualidade com o aumento do manuseio e transporte do produto. Frutos retirados diretamente da planta mostraram-se mais aptos a consumo após armazenagem por 21 dias (45%) do que frutos amostrados na CEASA (5,8%).231235Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    CRFs form protein–protein interactions with each other and with members of the cytokinin signalling pathway in Arabidopsis via the CRF domain

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    Cytokinin is a plant hormone essential for growth and development. The elucidation of its signalling pathway as a variant of the bacterial two-component signalling system (TCS) has led to a better understanding of how this hormone is involved in general plant processes. A set of cytokinin-regulated transcription factors known as cytokinin response factors (CRFs) have been described as a potential branch emanating from the TCS, yet little is known about how CRFs actually interact with each other and with members of the TCS pathway. Here the interactions of CRF proteins (CRF1–CRF8) using the yeast two-hybrid system and bimolecular fluorescence complementation in planta assays are described. It was found that CRFs are readily able to form both homo- and heterodimers with each other. The first analysis of CRF versus TCS pathway protein interactions is also provided, which indicates that CRFs (CRF1–CRF8) are able specifically to interact directly with most of the Arabidopsis histidine-phosphotransfer proteins (AHP1–AHP5) further solidifying their link to the cytokinin signalling pathway. In addition, the region of CRF proteins involved in these interactions was mapped and it was determined that the clade-specific CRF domain alone is sufficient for these interactions. This is the first described function for the CRF domain in plants

    Investigating the Mechanisms of Hyporesponse to Antiplatelet Approaches

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    Hyporesponsiveness, or resistance, to antiplatelet therapy may be a major contributor to poorer outcomes among cardiac patients and may be attributed to an array of mechanisms—both modifiable and unmodifiable. Recent evidence has uncovered clinical, cellular, and genetic factors associated with hyporesponsiveness. Patients with severe acute coronary syndromes (ACS), type 2 diabetes, and increased body mass index appear to be the most at risk for hyporesponsiveness. Addressing modifiable mechanisms may offset hyporesponsiveness, while recognizing unmodifiable mechanisms, such as genetic polymorphisms and diseases that affect response to antiplatelet therapy, may help identify patients who are more likely to be hyporesponsive. Hyporesponsive patients might benefit from different dosing strategies or additional antiplatelet therapies. Trials correlating platelet function test results to clinical outcomes are required. Results from these studies could cause a paradigm shift toward individualized antiplatelet therapy, improving predictability of platelet inhibition, and diminishing the likelihood for hyporesponsiveness. Copyright © 2008 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58554/1/20360_ftp.pd

    SARS-CoV-2 B.1.617 mutations L452 and E484Q are not synergistic for antibody evasion

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    SARS-CoV-2 B.1.617系統(俗称「インド株」)のL452R変異とE484Q変異は 中和抗体感受性の低下において、相加的な抵抗性を示さない. 京都大学プレスリリース. 2021-08-24.The SARS-CoV-2 B.1.617 variant emerged in the Indian state of Maharashtra in late 2020. There have been fears that two key mutations seen in the receptor binding domain L452R and E484Q would have additive effects on evasion of neutralising antibodies. We report that spike bearing L452R and E484Q confers modestly reduced sensitivity to BNT162b2 mRNA vaccine-elicited antibodies following either first or second dose. The effect is similar in magnitude to the loss of sensitivity conferred by L452R or E484Q alone. These data demonstrate reduced sensitivity to vaccine elicited neutralising antibodies by L452R and E484Q but lack of synergistic loss of sensitivity

    Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity

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    Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens
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