¿Es pertinente estudiar en México un postgrado en ciencias naturales, aun cuando existen múltiples retos en la ciencia?

En este escrito, se vierte una opinión acerca del porqué el gobierno de México, sin importar su filiación partidista, debe seguir apoyando a los estudiantes de postgrado en ciencias naturales. También se describen algunos de los retos y oportunidades que los postgraduados enfrentan durante su formación académica, así como la confianza de que la inversión en su educación no es un dinero de fondo perdido, sino una inversión en capital humano que facilitará la transición del país hacia la economía del conocimiento y nivel de país desarrollado, pero sobre todo a la formación de un país con personas más críticas y conscientes acerca de sus necesidades de desarrollo técnico e intelectual

Early Detection of the Fungal Banana Black Sigatoka Pathogen Pseudocercospora fijiensis by an SPR Immunosensor Method

Black Sigatoka is a disease that occurs in banana plantations worldwide. This disease is caused by the hemibiotrophic fungus Pseudocercosporafijiensis, whose infection results in a significant reductioninbothproductqualityandyield. Therefore,detectionandidentificationintheearlystages of this pathogen in plants could help minimize losses, as well as prevent the spread of the disease to neighboring cultures. To achieve this, a highly sensitive SPR immunosensor was developed to detect P. fijiensis in real samples of leaf extracts in early stages of the disease. A polyclonal antibody (anti-HF1), produced against HF1 (cell wall protein of P. fijiensis) was covalently immobilized on agold-coatedchipviaamixedself-assembledmonolayer(SAM)ofalkanethiolsusingtheEDC/NHS method.Theanalyticalparametersofthebiosensorwereestablished, obtainingalimitofdetectionof 11.7 µg mL−1, a sensitivity of 0.0021 units of reflectance per ng mL−1 and a linear response range for the antigen from 39.1 to 122 µg mL−1. No matrix effects were observed during the measurements of real leaf banana extracts by the immunosensor. To the best of our knowledge, this is the first research into the development of an SPR biosensor for the detection of P. fijiensis, which demonstrates its potential as an alternative analytical tool for in-field monitoring of black Sigatoka disease

Chemical management in fungicide sensivity of Mycosphaerella fijiensis collected from banana fields in México

The chemical management of the black leaf streak disease in banana caused by Mycosphaerella fijiensis (Morelet) requires numerous applications of fungicides per year. However this has led to fungicide resistance in the field. The present study evaluated the activities of six fungicides against the mycelial growth by determination of EC50 values of strains collected from fields with different fungicide management programs: Rustic management (RM) without applications and Intensive management (IM) more than 25 fungicide application/year. Results showed a decreased sensitivity to all fungicides in isolates collected from IM. Means of EC50 values in mg L-1 for RM and IM were: 13.25 ± 18.24 and 51.58 ± 46.14 for azoxystrobin, 81.40 ± 56.50 and 1.8575 ± 2.11 for carbendazim, 1.225 ± 0.945 and 10.01 ± 8.55 for propiconazole, 220 ± 67.66 vs. 368 ± 62.76 for vinclozolin, 9.862 ± 3.24 and 54.5 ± 21.08 for fludioxonil, 49.2125 ± 34.11 and 112.25 ± 51.20 for mancozeb. A molecular analysis for β-tubulin revealed a mutation at codon 198 in these strains having an EC50 greater than 10 mg L-1 for carbendazim. Our data indicate a consistency between fungicide resistance and intensive chemical management in banana fields, however indicative values for resistance were also found in strains collected from rustic fields, suggesting that proximity among fields may be causing a fungus interchange, where rustic fields are breeding grounds for development of resistant strains. Urgent actions are required in order to avoid fungicide resistance in Mexican populations of M. fijiensis due to fungicide management practices

Fungal Effectoromics: A World in Constant Evolution

Effectors are small, secreted molecules that mediate the establishment of interactions in nature. While some concepts of effector biology have stood the test of time, this area of study is ever-evolving as new effectors and associated characteristics are being revealed. In the present review, the different characteristics that underly effector classifications are discussed, contrasting past and present knowledge regarding these molecules to foster a more comprehensive understanding of effectors for the reader. Research gaps in effector identification and perspectives for effector application in plant disease management are also presented, with a focus on fungal effectors in the plant-microbe interaction and interactions beyond the plant host. In summary, the review provides an amenable yet thorough introduction to fungal effector biology, presenting noteworthy examples of effectors and effector studies that have shaped our present understanding of the field

Microbial Effectors: Key Determinants in Plant Health and Disease

Effectors are small, secreted molecules that alter host cell structure and function, thereby facilitating infection or triggering a defense response. Effectoromics studies have focused on effectors in plant–pathogen interactions, where their contributions to virulence are determined in the plant host, i.e., whether the effector induces resistance or susceptibility to plant disease. Effector molecules from plant pathogenic microorganisms such as fungi, oomycetes and bacteria are major disease determinants. Interestingly, the effectors of non-pathogenic plant organisms such as endophytes display similar functions but have different outcomes for plant health. Endophyte effectors commonly aid in the establishment of mutualistic interactions with the plant and contribute to plant health through the induction of systemic resistance against pathogens, while pathogenic effectors mainly debilitate the plant’s immune response, resulting in the establishment of disease. Effectors of plant pathogens as well as plant endophytes are tools to be considered in effectoromics for the development of novel strategies for disease management. This review aims to present effectors in their roles as promotors of health or disease for the plant host

EffHunter: A Tool for Prediction of Effector Protein Candidates in Fungal Proteomic Databases

Pathogens are able to deliver small-secreted, cysteine-rich proteins into plant cells to enable infection. The computational prediction of effector proteins remains one of the most challenging areas in the study of plant fungi interactions. At present, there are several bioinformatic programs that can help in the identification of these proteins; however, in most cases, these programs are managed independently. Here, we present EffHunter, an easy and fast bioinformatics tool for the identification of effectors. This predictor was used to identify putative effectors in 88 proteomes using characteristics such as size, cysteine residue content, secretion signal and transmembrane domains

Las proteínas DING, una familia con intrigantes funciones celulares

La familia de las proteínas DING recibe este nombre porque en especies filogenéticamente distantes, dichos aminoácidos están altamente conservados en el extremo N-terminal. Sus integrantes tienen un peso molecular ~40 kDa, están relacionadas con el metabolismo del fosfato, son secretadas y en su mayoría poseen actividad enzimática de fosfatasa. Inicialmente se creyó que las proteínas DING eran exclusivas de Pseudomonas sp., pero ahora se sabe que están distribuidas en los diferentes reinos biológicos. El descubrimiento de esta familia se fundamentó en la secuenciación de aminoácidos debido a que, con excepción de Pseudomonas fluorescens, P. aeruginosa y algunos otros procariontes, los genes que las codifican no han sido encontrados en las bases de genes de los eucariontes cuyos genomas han sido ya secuenciados. Las proteínas DING tienen funciones biológicas controversiales y por ello están siendo objeto de intensa investigación. En células animales se les ha asociado con la aparición de enfermedades como el cáncer de mama y la caquexia, pero también con la protección contra la arterioesclerosis y la litiasis. En vegetales, algunas proteínas DING muestran propiedades citotóxicas sobre células tumorales o de inhibición de la replicación del virus VIH-1. La evidencia biológica muestra que el mecanismo de acción de las proteínas DING puede ser variado y el resultado contrastante. Dada la potencial aplicación terapéutica de estas proteínas, en esta revisión se describen los hallazgos que se han realizando en esta familia debido a que previamente a su aplicación es necesario entender los mecanismos que regulan sus funciones. Abstract The DING family of proteins called because in phylogenetically distant species, these amino acids are highly conserved in the N- terminal. The members have a molecular weight of ~40 kDa, are related to phosphate metabolism, are secreted and have mostly phosphatase enzymatic activity. Initially it was believed that DING proteins were unique to Pseudomonas sp., but is now known they are distributed in different biological kingdoms. The discovery of this family was based on the sequencing of amino acids because, with the exception of Pseudomonas fluorescens, P. aeruginosa and some other prokaryotes, the genes that encode them have not been found on the basis of genes of eukaryotes whose genomes have already been sequenced. The DING proteins have controversial biological functions and are therefore the subject of intense research. In animal cells they have been associated with the occurrence of diseases such as breast cancer and cachexia, but also to protection against atherosclerosis and gallstones. In plants, DING proteins exhibit some cytotoxic properties on tumor cells or on inhibiting the replication of HIV-1 virus. Biological evidence shows that the mechanism of action of the DING proteins can be varied and with contrasting results. Given the potential therapeutic application of these proteins, in this review, we described the findings that have been made in this family, since before its exploitation it is necessary to understand the mechanisms that regulate their functions. Keywords: Hypericum perforatum; Pseudomonas sp., DING proteins, anticancer drugs