Author: DAISY DE LA CARIDAD PEREZ BRITO

Physical characteristics of the leaves and latex of papaya plants infected with the Papaya meleira virus

DAISY DE LA CARIDAD PEREZ BRITO (2016)

Sticky disease, which is caused by Papaya meleira virus (PMeV), is a significant papaya disease in Brazil and Mexico, where it has caused severe economic losses, and it seems to have spread to Central and South America. Studies assessing the pathogen-host interaction at the nano-histological level are needed to better understand the mechanisms that underlie natural resistance. In this study, the topography and mechanical properties of the leaf midribs and latex of healthy and PMeV-infected papaya plants were observed by atomic force microscopy and scanning electron microscopy. Healthy plants displayed a smooth surface with practically no roughness of the leaf midribs and the latex and a higher adhesion force than infected plants. PMeV promotes changes in the leaf midribs and latex, making them more fragile and susceptible to breakage. These changes, which are associated with increased water uptake and internal pressure in laticifers, causes cell disruption that leads to spontaneous exudation of the latex and facilitates the spread of PMeV to other laticifers. These results provide new insights into the papaya-PMeV interaction that could be helpful for controlling papaya sticky disease.

Article

PAPAYA STICKY DISEASE PAPAYA MELEIRA VIRUS LEAF MIDRIBS BIOLOGÍA Y QUÍMICA

Detección molecular de fitoplasmas en nopal tunero (Opuntia ficus-indica) con síntomas de engrosamiento del cladodio

Molecular detection of phytoplasmas in prickly pear (Opuntia ficus-indica) with thickening of the cladodio

ALBA PRISCILIA SUASTE DZUL REYNA ISABEL ROJAS MARTINEZ EMMA ZAVALETA MEJIA Daisy de la Caridad Pérez Brito (2012)

Durante 2010 se detectaron en la zona tunera de Nopaltepec, Estado de México, plantas de nopal con síntomas de deformación y engrosamiento del cladodio, mosaico, amarillamiento, proliferación y deformación de frutos en toda la planta o en parte de ella. Dado que el síndrome se ha relacionado con la infección por fitoplasmas, el objetivo de esta investigación fue detectar mediante la Reacción en Cadena de la Polimerasa (PCR), la presencia de fitoplasmas en diferentes estratos del cladodio y raíz de plantas de nopal. El ADN extraído de las muestras de plantas con síntomas y asintomáticas, se amplificó primero con los iniciadores universales P1/P7 y P1/Tint, y posteriormente mediante PCR anidada utilizando los iniciadores R16F2/R16R2, se obtuvo un fragmento de 1 200 pb en todas las muestras con los síntomas antes mencionados. El análisis de los patrones de restricción generados con las endonucleasas HaeIII, KpnI y MseI (TrU91), reveló que el fitoplasma pertenece al grupo 16SrXIII-Mexican periwinkle virescence.

Article

MOLLICUTES PCR ANIDADA RFLP-PCR GEN 16S RRNA BIOLOGÍA Y QUÍMICA BIOLOGÍA Y QUÍMICA

A current overview of the Papaya meleira virus, an unusual plant virus

ANUAR AHMED MAGAÑA ALVAREZ DAISY DE LA CARIDAD PEREZ BRITO RAUL TAPIA TUSSELL (2015)

Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA) genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex.

Article

PAPAYA STICKY DISEASE DSRNA GENOME VIRUS PHYTOPATHOGENIC VIRUS LATICIFERS COLONIZATION BIOLOGÍA Y QUÍMICA

Genetic structure and demographic history of Colletotrichum gloeosporioides sensu lato and C. truncatum isolates from Trinidad and Mexico

DAISY DE LA CARIDAD PEREZ BRITO CLAUDIA GUADALUPE TORRES CALZADA RAUL TAPIA TUSSELL (2013)

C. gloeosporioides sensu lato is one of the most economically important post-harvest diseases affecting papaya production worldwide. There is currently no information concerning the genetic structure or demographic history of this pathogen in any of the affected countries. Knowledge of molecular demographic parameters for different populations will improve our understanding of the biogeographic history as well as the evolutionary and adaptive potential of these pathogens. In this study, sequence data for ACT, GPDH, β-TUB and ITS gene regions were analyzed for C. gloeosporioides sensu lato and C. truncatum isolates infecting papaya in Trinidad and Mexico in order to determine the genetic structure and demographic history of these populations. Results: The data indicated that Mexico is the ancestral C. gloeosporioides sensu lato population with asymmetrical migration to Trinidad. Mexico also had the larger effective population size but, both Mexico and Trinidad populations exhibited population expansion. Mexico also had greater nucleotide diversity and high levels of diversity for each gene. There was significant sub-division of the Trinidad and Mexico populations and low levels of genetic divergence among populations for three of the four gene regions; β-TUB was shown to be under positive selection. There were also dissimilar haplotype characteristics for both populations. Mutation may play a role in shaping the population structure of C. gloeosporioides sensu lato isolates from Trinidad and from Mexico, especially with respect to the ACT and GPDH gene regions. There was no evidence of gene flow between the C. truncatum populations and it is possible that the Mexico and Trinidad populations emerged independently of each other. Conclusions: The study revealed relevant information based on the genetic structure as well as the demographic history of two fungal pathogens infecting papaya, C. gloeosporioides sensu lato and C. truncatum, in Trinidad and Mexico. Understanding the genetic structure of pathogen populations will assist in determining the evolutionary potential of the pathogen and in identifying which evolutionary forces may have the greatest impact on durability of resistance. Intervention strategies that target these evolutionary forces would prove to be the most practical.

Article

COLLETOTRICHUM SPP. GENETIC DIFFERENTIATION MIGRATION POPULATION STRUCTURE BIOLOGÍA Y QUÍMICA

Sensitivity of colletotrichum truncatum to four fungicides and characterization of thiabendazole-resistant isolates

DAISY DE LA CARIDAD PEREZ BRITO CLAUDIA GUADALUPE TORRES CALZADA RAUL TAPIA TUSSELL INOCENCIO HIGUERA CIAPARA RODOLFO MARTIN MEX ANGEL NEXTICAPAN GARCEZ (2015)

Anthracnose, caused by Colletotrichum truncatum (syn. C. capsici), has become a common disease of tropical crops, severely affecting the quantity and quality of fruit and seed and, therefore, reducing their market value. For years, chemical control has been extensively used for managing this disease. However, the appearance of isolates that are resistant to the most commonly employed fungicides is increasingly widespread. Twenty C. truncatum isolates from pepper, papaya, and physic nut were rested in vitro against four fungicides to determine their sensitivity. All evaluated isolates were resistant to azoxystrobin and thiabendazole and susceptible to cyprodinil + fludioxonil and mancozeb. To determine the molecular mechanism conferring thiabendazole resistance, the TUB-2 gene was characterized, revealing a glutamic acid to alanine substitution at position 198 in 6 of the 20 isolates that were tested. This work confirms the emergence of benzimidazole-based fungicide resistance in C. truncatum populations and highlights the need for monitoring fungicide sensitivity as an essential activity for the development of effective control schemes.

Article

CYTOCHROME-B GENE NATURAL TOXIC COMPOUNDS BOTRYTIS-CINEREA QOI FUNGICIDES MYCOSPHAERELLA-GRAMINICOLA BIOLOGÍA Y QUÍMICA

A fast, simple, and reliable high-yielding method for DNA extraction from different plant species

RAUL TAPIA TUSSELL ANDRES FELIPE DE JESUS QUIJANO RAMAYO RAFAEL ANTONIO ROJAS HERRERA FRANCISCO ALFONSO LARQUE SAAVEDRA DAISY DE LA CARIDAD PEREZ BRITO (2005)

Genetic studies and pathogen detection in plants using molecular methods require the isolation of DNA from a large number of samples in a short time span. A rapid and versatile protocol for extracting high-quality DNA from different plant species is described. This method yields from 1 to 2 mg of DNA per gram of tissue. The absorbance ratios (A260/A280) obtained ranged from 1.6 to 2.0. A minimal presence of contaminating metabolites (as polymerase chain reaction [PCR] inhibitors) in samples and a considerable savings in reagents are characteristics of this protocol, as well as the low cost of the analysis per sample. The quality of the DNA was suitable for PCR amplification.

Article

AGAVACEAE CARIACACEAE CUCURBITACEAE DNA ISOLATION GRAMINAEAE PALMAE BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA

Laccase gene expression and vinasse biodegradation by Trametes hirsuta strain Bm-2

RAUL TAPIA TUSSELL DAISY DE LA CARIDAD PEREZ BRITO CLAUDIA GUADALUPE TORRES CALZADA ALBERTO CORTES VELAZQUEZ LILIANA MARIA ALZATE GAVIRIA RUBI DEL ROSARIO CHABLE VILLACIS SARA ELENA SOLIS PEREIRA (2015)

Vinasse is the dark-colored wastewater that is generated by bioethanol distilleries from feedstock molasses. The vinasse that is generated from molasses contains high amounts of pollutants, including phenolic compounds and melanoindin. The goal of this work was to study the expression of laccase genes in the Trametes hirsuta strain Bm-2, isolated in Yucatan, Mexico, in the presence of phenolic compounds, as well as its effectiveness in removing colorants from vinasse. In the presence of all phenolic compounds tested (guaiacol, ferulic acid, and vanillic acid), increased levels of laccase-encoding mRNA were observed. Transcript levels in the presence of guaiacol were 40 times higher than those in the control. The lcc1 and lcc2 genes of T. hirsuta were differentially expressed; guaiacol and vanillin induced the expression of both genes, whereas ferulic acid only induced the expression of lcc2. The discoloration of vinasse was concomitant with the increase in laccase activity. The highest value of enzyme activity (2543.7 U/mL) was obtained in 10% (v/v) vinasse, which corresponded to a 69.2% increase in discoloration. This study demonstrates the potential of the Bm-2 strain of T. hirsuta for the biodegradation of vinasse.

Article

TRAMETES HIRSUTA LACASSES GENE EXPRESSION BIODEGRADATION VINASSE BIOLOGÍA Y QUÍMICA BIOLOGÍA Y QUÍMICA

Ultrastructural characterization of Phakopsora jatrophicola pathogen of Jatropha curcas in Yucatan, Mexico

Caracterización ultraestructural de Phakopsora jatrophicola patógeno de Jatropha curcas en Yucatán, México

ABRIL JESUS DIAZ BRAGA RAUL TAPIA TUSSELL Tanit Toledano Thompson Rodolfo Martín Mex ANGEL NEXTICAPAN GARCEZ ANDRES FELIPE DE JESUS QUIJANO RAMAYO Daisy de la Caridad Pérez Brito (2016)

Physic nut (Jatropha curcas) has been considered worldwide as a source of seed oil for the production of biofuel. In Yucatan, Mexico, this crop has been affected by rust caused by Phakopsora jatrophicola (syn. P. arthuriana), an obligate biotrophic fungus, which has become a major constraint in obtaining expected yields. Currently, little is known about the biology of P. jatrophicola. Since there are no previous studies at ultramicroscopic morphology level, we conducted the first Scanning electron microscopy (SEM) examination of this species and a bioassay on J. curcas detached leaves in order to test the spore infectivity. SEM analysis revealed erumpent uredinia with 25 to 35 μm diameter open pore, containing 23 μm length x 11 μm wide equinulated urediniospores. Moreover, spores harvested from Physic nut leaves were able to produce new pustules after 13 days of inoculation on healthy detached J. curcas leaves. These results pro-vide the basis for further researches of this host-pathogen interaction, and may be useful in the development of new molecular methods for diagnostic of this specie.

Article

SCANNING ELECTRON MICROSCOPY UREDINIOSPORES RUST PHYSIC NUT BIOLOGÍA Y QUÍMICA BIOLOGÍA Y QUÍMICA

First report of papaya meleira virus (PMeV) in Mexico

DAISY DE LA CARIDAD PEREZ BRITO RAUL TAPIA TUSSELL ALBERTO CORTES VELAZQUEZ ANDRES FELIPE DE JESUS QUIJANO RAMAYO ANGEL NEXTICAPAN GARCEZ RODOLFO MARTIN MEX (2012)

Papaya meleira virus (PMeV), causal agent of meleira or sticky disease, is a double-stranded RNA (dsRNA) virus which has been previously reported only in Brazil. A study was carried out in order to verify the presence and occurrence of PMeV in Mexico. Latex samples from symptomatic and asymptomatic papaya fruits were collected in Quintana Roo state papaya orchards, where the first symptoms of PMeV were observed, and from 29 different municipalities located in ten papaya producer states in Mexico. A molecular protocol based on nucleic acid extraction was used for the diagnosis and a virus 12 Kb dsRNA distinctive band was observed in all PMeV infected plants. Around 46% of the evaluated plants were positive for this pathogen. Presence of the virus had been confirmed in seven states indicating the potential damage that PMeV could cause in the papaya crop in Mexico. The molecular analysis used allowed the diagnosis of infected plants without symptoms and facilitated the diagnosis in flowers and small papaya fruits also. The early diagnosis of PMeV will allow papaya producers to take appropriate and timely control measures. This is the first report of Papaya meleira virus in Mexico.

Article

PAPAYA MELEIRA VIRUS STICKY DISEASE DSRNA NUCLEIC ACID ANALYSIS BIOLOGÍA Y QUÍMICA