101 research outputs found

    Rapid staining method to detect and identify downy mildew (Peronospora belbahrii) in basil1

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    • Premise of the study: Demand for fresh-market sweet basil continues to increase, but in 2009 a new pathogen emerged, threatening commercial field/greenhouse production and leading to high crop losses. This study describes a simple and effective staining method for rapid microscopic detection of basil downy mildew (Peronospora belbahrii) from leaves of basil (Ocimum basilicum). • Methods and Results: Fresh leaf sections infected with P. belbahrii were placed on a microscope slide, cleared with Visikol™, and stained with iodine solution followed by one drop of 70% sulfuric acid. Cell walls of the pathogen were stained with a distinct coloration, providing a high-contrast image between the pathogen and plant. • Conclusions: This new staining method can be used successfully to identify downy mildew in basil, which then can significantly reduce its spread if identified early, coupled with mitigation strategies. This technique can facilitate the control of the disease, without expensive and specialized equipment

    Algal and cyanobacterial lectins and their antimicrobial properties

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    Lectins are proteins with a remarkably high affinity and specificity for carbohydrates. Many organisms naturally produce them, including animals, plants, fungi, protists, bacteria, archaea, and viruses. The present report focuses on lectins produced by marine or freshwater organisms, in particular algae and cyanobacteria. We explore their structure, function, classification, and antimicrobial properties. Furthermore, we look at the expression of lectins in heterologous systems and the current research on the preclinical and clinical evaluation of these fascinating molecules. The further development of these molecules might positively impact human health, particularly the prevention or treatment of diseases caused by pathogens such as human immunodeficiency virus, influenza, and severe acute respiratory coronaviruses, among others.Fil: Fernández Romero, José Abel. City University of New York. The City College of New York; Estados Unidos. Center for Biomedical Research; Estados UnidosFil: Paglini, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; ArgentinaFil: Priano, Christine. City University of New York. The City College of New York; Estados UnidosFil: Koroch, Adolfina. City University of New York. The City College of New York; Estados UnidosFil: Rodríguez, Yoel. City University of New York. The City College of New York; Estados UnidosFil: Sailer, James. Center for Biomedical Research; Estados UnidosFil: Teleshova, Natalia. Center for Biomedical Research; Estados Unido

    An improved clearing and mounting solution to replace chloral hydrate in microscopic applications1

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    • Premise of the study: This study presents Visikol™, a new proprietary formulation that can be used as an efficient replacement for chloral hydrate as a clearing agent for microscopic examination. In the United States, chloral hydrate is regulated and therefore difficult to acquire. • Methods and Results: Fresh and dry samples of the following plants: ginger (Zingiber officinale), maté (Ilex paraguariensis), lime basil (Ocimum americanum), oregano (Origanum vulgare), and mouse-ear cress (Arabidopsis thaliana), were cleared using Visikol or chloral hydrate solution and compared using a light microscope. • Conclusions: This new method can be used successfully to clear specimens, allowing identification of diagnostic characteristics for the identification of plant materials. Visikol is as effective as chloral hydrate in providing clarity and resolution of all tissues examined. Tissues become transparent, allowing observation of deeper layers of cells and making it effective in research, botanical and quality control, and for educational applications

    The role of ascorbic acid in the preservation or degradation of chlorophyll in oat leaves

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    Cuando segmentos de hojas de avena son incubados en agua, se verifica una mayor pérdida de clorofilas en condiciones de oscuridad que en luz.La adición de ácido ascórbico al medio de incubación invierte este comportamiento,induciendo una menor degradación de clorofilas en oscuridad y un incremento del blanqueo en condiciones de luz. El efecto en luz es acompañado por un aumento en la producción de malondialdehido y en la permeabilidad de membranas, lo que sugiere que la mayor pérdida de clorofilas en luz, inducida por ascorbato, podría estar mediada por radicales libres del oxígeno. La destrucción de clorofilas aisladas incubadas en presencia de los reactivos de Fenton y su prevención con benzoato sugiere que el radical hidroxilo ( OH) puede ser el radical implicado.La adición de ciclo heximida al medio de incubación impide el blanqueo,sugiriendo la existencia de una vía enzimática de degradación del pigmento .La menor pérdida de clorofilas en oscuridad producida por ascórbico es acompañada por la inactivación de la fenol peroxidasa, enzima que fuera implicada en la destrucción del pigmento.Los resultados sugieren que la aceleración de la pérdida de clorofilas en luz, causada por ácido ascórbico, estaría relacionada al incremento de procesos fotooxidativos y el efecto en oscuridad a la inactivación de enzima/s capaces de degradar ciorofilas como la guaiacoi peroxidasa
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