Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection

Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection

The U-Box Protein CMPG1 Is Required for Efficient Activation of Defense Mechanisms Triggered by Multiple Resistance Genes in Tobacco and Tomato

We previously identified three Avr9/Cf-9 Rapidly Elicited (ACRE) genes essential for Cf-9– and Cf-4–dependent hypersensitive response (HR) production in Nicotiana benthamiana. Two of them encode putative E3 ubiquitin ligase components. This led us to investigate other ACRE genes associated with the ubiquitination pathway. ACRE74 encodes a U-box E3 ligase homolog, highly related to parsley (Petroselinum crispum) CMPG1 and Arabidopsis thaliana PLANT U-BOX20 (PUB20) and PUB21 proteins, and was called Nt CMPG1. Transcript levels of Nt CMPG1 and the homologous tomato (Solanum lycopersicum) Cmpg1 are induced in Cf9 tobacco (Nicotiana tabacum) and Cf9 tomato after Avr9 elicitation. Tobacco CMPG1 possesses in vitro E3 ligase activity. N. benthamiana plants silenced for Nt CMPG1 show reduced HR after Cf-9/Avr9 elicitation, while overexpression of Nt CMPG1 induces a stronger HR in Cf9 tobacco plants after Avr9 infiltration. In tomato, silencing of Cmpg1 decreased resistance to Cladosporium fulvum. Overexpression of epitope-tagged tobacco CMPG1 mutated in the U-box domain confers a dominant-negative phenotype. We also show that Nt CMPG1 is involved in the Pto/AvrPto and Inf1 responses. In summary, we show that the E3 ligase Nt CMPG1 is essential for plant defense and disease resistance

Estudio de la función endotelial mediante tomografía por emisión de positrones en pacientes con hipercolesterolemia

La hipercolesterolemia predispone al desarrollo de disfunción endotelial (DE) y la DE precipita la aterogénesis. La DE ocurre temprano en el curso de la aterogénesis y es considerada un marcador pronóstico para el desarrollo de cardiopatía isquémica. Objetivo: Evaluar la función endotelial (FE) mediante tomografía por emisión de positrones (PET) de pacientes asintomáticos con dislipidemia sin antecedente de cardiopatía isquémica ni tratamiento hipolipemiante previo. Material y métodos: Se estudiaron catorce pacientes asintomáticos con diagnóstico reciente (< 6 meses) de dislipidemia mediante un perfil lipídico, glucosa en sangre y un estudio de 13N-amonio PET en tres fases: reposo, prueba presora con frío (CPT) y estrés farmacológico con adenosina. Se evaluó su FE mediante el cálculo de la reserva de flujo coronario (RFC), índice de vasodilatación endotelio-dependiente (IVED) y porcentaje del incremento del flujo coronario en CPT (% Δ FC). Resultados: El 79% de los pacientes tuvieron disfunción endotelial (DE), y todos los valores de los pacientes con dislipidemia fueron menores a los parámetros normales previamente publicados: flujo coronario (FC) en reposo (FCR) 0.44 ± 0.12 vs 0.57 ± 0.147 (p = 0.002), FC en CPT 0.57 ± 0.17 vs 0.88 ± 0.26 (p = 0.001), FC en estrés (FCE) 1.24 ± 0.05 vs 1.81 ± 0.35 (p = 0.005), IVED 1.28 ± 0.25 vs 1.53 ± 0.24 (p 0.017), RFC 2.79 ± 0.94 vs 3.15 ± 0.48 (p 0.198) y % Δ FC 29.08 ± 24.62% vs 53 ± 24.60% (p 0.022). Conclusiones: Los pacientes asintomáticos en etapas tempranas de dislipidemia tienen mayor prevalencia de DE que puede ser identificada mediante 13N-amonio PET