Author: J Sergio Casas Flores

Efecto de la limitación de fosfato sobre la conidiación de Trichoderma atroviride y mutantes ciegas a la luz

The influence of phosphate limitation on conidiation in Trichoderma atroviride and light blind mutants

MACARIO OSORIO CONCEPCION J SERGIO CASAS FLORES CARLOS CORTES PENAGOS (2013)

"Los eventos moleculares asociados a la conidiación inducida por luz en Trichoderma están regulados por el complejo formado por las proteínas BLR-1 y BLR-2, donde la primera actúa como fotorreceptor y ambas tienen actividad como factor de transcripción. Las cepas mutantes nulas en los genes blr de T. atroviride pierden la capacidad de responder al estímulo luminoso y son consideradas "mutantes ciegas". La limitación de algunos nutrientes esenciales también desencadenan la conidiación en T. atroviride. La influencia de bajas concentraciones de fosfato inorgánico (Pi) en el medio de cultivo sobre la fotoconidiación de la cepa silvestre y las mutantes blr de T. atroviride fue probada. Todas las cepas utilizadas mostraron el desarrollo de conidias bajo concentraciones limitantes de Pi (hasta 0.1 mM) en ausencia de la luz. Los resultados indican que la limitación de Pi es un factor desencadenante del proceso de conidiación a través de una vía independiente a la mediada por las proteínas BLR."

"Molecular events associated with photoconidiation of Trichoderma are regulated by the BLR-1 and BLR-2 protein complex, where the first plays an essential role as sensor, and both function as a transcriptional factor. Null mutant strains of blr genes in T. atroviride are unable to respond to light stimulation and are then considered blind mutants. Limited concentration of essential nutrients in the media is a condition that triggers conidiation in T. atroviride. In the present study we show the influence of limited concentration of inorganic phosphate (Pi) in the media on photoconidiation in T. atroviride and two blr null mutants. All strains tested showed the development of conidial structures when low levels of Pi (0.1 mM) were present in the absence of light. The data showed that sensing environmental cues such as phosphate limitation is independent of BLR proteins pathway."

Article

Hypocrea Mutantes blr Nutrición Morfogénesis Esporulación BIOLOGÍA Y QUÍMICA

Cepa de Trichoderma harzianum con actividad antagónica contra hongos fitopatógenos, composiciones que la contienen y uso de la misma

Strain of Trichoderma harzianum with an antagonistic activity against plant pathogens, compositions containing the same and use thereof

ALFREDO HERIBERTO HERRERA ESTRELLA J SERGIO CASAS FLORES MIGUEL ANGEL SILVA FLORES (2015)

"La presente invención describe y reclama una cepa novedosa del hongo Trichoderma harzianum NRRL-50453. La utilización de esta cepa disminuye considerablemente el uso abonos y de pesticidas químicos cuya fabricación y uso dañan el medio ambiente y la salud humana."

"The present invention describes and claims a novel strain from the Trichoderma harzianum fungus NRRL-50453. The use of this strain reduces in a substantial manner the application of manures and chemical pesticides which manufacture and use damage the environment and human health."

Patent

A01N63/04 C12N1/14 BIOLOGÍA Y QUÍMICA

Cepas transformantes del hongo micoparásito Trichoderma spp. promotoras de crecimiento y resistencia a enfermedades fungicas y bacterianas en plantas solanaceas, composiciones que las contienen, procedimiento de aplicación y uso de las mismas

Transformant strains of the mycoparasite fungus Trichoderma spp. which promote the growth and resistance to fungal and bacterial diseases in solanaceae plants, composition containing the same, application process and use thereof

ALFREDO HERIBERTO HERRERA ESTRELLA J SERGIO CASAS FLORES GERARDO RAFAEL ARGUELLO ASTORGA MIGUEL ANGEL SALAS MARINA (2009)

"La presente invención describe y reclama cepas transformantes novedosas del hongo Trichoderma ssp., capaces de promover el crecimiento y la resistencia a fitopatógenos en plantas de interés agronómico de una manera significativa en comparación con las cepas convencionales. La utilización de estas cepas disminuyen considerablemente el uso abonos y de pesticidas químicos cuya fabricación y uso dañan el medio ambiente y la salud humana."

"The present invention describes and claims novel transformant strains of the Trichoderma ssp fungus, which promote the growth and resistance to phytopathogens in plants of agricultural interests in a significant manner unlike traditional strains. The use of said strains reduces in a substantial manner the application of manures and chemical pesticides which manufacture and usage damage the environment and human health."

Patent

C12N15/00 BIOLOGÍA Y QUÍMICA

Cepa de Trichoderma citrinoviride con actividad antagónica contra hongos fitopatógenos y de promoción de crecimiento, composiciones que la tienen y uso de la misma

Strain of Trichoderma citrinoviride acting as antagonist of phytopatoghen fungi and grouth promoter, compositions containing the same and use thereof

ALFREDO HERIBERTO HERRERA ESTRELLA J SERGIO CASAS FLORES MIGUEL ANGEL SALAS MARINA (2013)

"La presente invención describe y reclama una cepa novedosa del hongo Trichoderma citrinoviride NRRL-50452, capaz de promover el crecimiento y la resistencia a fitopatógenos en plantas de interés agronómico de una manera muy superior en comparación con las cepas comerciales existentes hoy en día. La utilización de esta cepa disminuye considerablemente el uso abonos y de pesticidas químicos cuya fabricación y uso dañan el medio ambiente y la salud humana."

"The present invention describes and claims a novel strain of the Trichoderma citrinoviride NRRL-50452 fungus, which promotes the growth and resistance to phytopathogens in plants of agricultural interest in a significant manner unlike traditional strains. The use of said strain reduces in a substantial manner the application of manures and chemical pesticides which manufacture and use damage the environment and human health."

Patent

A01N63/00 C12N15/00 BIOLOGÍA Y QUÍMICA

Regulación del inicio de la esporulación e histidina cinasas: un análisis comparativo entre bacillus subtilis y el grupo bacillus cereus

Sporulation start and hystidine kinase regulation: a comparative analysis of bacillus subtilis the group of bacillus cereus

LAURA MARGARITA CASTAÑEDA SANDOVAL J SERGIO CASAS FLORES MARIA AUXILIADORA ISLAS OSUNA (2009)

"La esporulación, que es una respuesta de quorum sensing, es un proceso de diferenciación celular mediado por moléculas de señalización, señales fisiológicas y ambientales. Se sabe que Bacillus subtilis detecta las señales metabólicas y ambientales y éstas son integradas a un sistema de transferencia secuencial de fosfatos. Las señales son detectadas por histidina cinasas que se autofosforilan y fosforilan, a su vez, a proteínas que actúan como reguladores de respuesta y activan la expresión de genes específicos de esporulación. Dada la importancia de B. cereus desde el punto de vista epidemiológico, el potencial para bioterrorismo de B. anthracis y la importancia en biotecnología agrícola de B. thuringiensis, la investigación sobre los mecanismos moleculares de señalización y la regulación del inicio de la esporulación en estas bacterias del grupo B. cereus reviste especial interés. En esta revisión se discute la literatura sobre este tema, haciendo hincapié en las histidina cinasas y en el análisis comparativo de los genomas de B. subtilis y del grupo de B. cereus, en cuanto a las secuencias de posibles histidina cinasas y reguladores de respuesta. Cabe destacar que en los genomas del grupo B. cereus hay mayor número de histidina cinasas (10 a 14) y de reguladores de respuesta (7 a 11) putativos que en B. subtilis (6 histidina cinasas y 6 reguladores de respuesta), lo cual sugiere una mayor capacidad para responder a estímulos ambientales y metabólicos en estas bacterias."

"Sporulation is a quorum sensing response and a cellular differentiation process regulated by signalling molecules and physiological and environmental signals. The regulation of sporulation initiation has been extensively studied in Bacillus subtilis and occurs through phosphorelay. B. subtilis detects metabolic and environmental signals through histidine kinases that are autophosphorylated and then transfer the phosphate group to response regulators, activating the expression of sporulation genes. However, there are other important sporulated bacilli like those from the B. cereus group. B. cereus toxins are related to food-borne intoxication, B. anthracis may be used as biological weapon in bioterrorism, and B. thuringiensis is an excellent biological control agent. Therefore, it is critical to understand the signalling processes that control sporulation initiation and the toxin synthesis. This review summarizes known literature about regulation of initiation of sporulation in the B. cereus group focusing in the role of histidine kinases and the putative open reading frames of these sensors in B. subtilis and B. thuringiensis. The genomes of the B. cereus group have 10 to 14 putative histidine kinases and 7 to 11 response regulators, compared to 6 histidine kinases and 6 response regulators in B. subtilis, implying that this last bacteria should have a lower capacity to respond to environmental and metabolic signals."

Article

Bacillus subtilis Bacillus thuringiensis Cry Esporulación Histidina Cinasa Transducción de Señales BIOLOGÍA Y QUÍMICA

Light induces oxidative damage and protein stability in the fungal photoreceptor Vivid

CARMEN NOEMI HERNANDEZ CANDIA J Sergio Casas Flores Braulio Gutiérrez Medina (2018)

"Flavin-binding photoreceptor proteins sense blue-light (BL) in diverse organisms and have become core elements in recent optogenetic applications. The light-oxygen-voltage (LOV) protein Vivid (VVD) from the filamentous fungus Neurospora crassa is a classic BL photoreceptor, characterized by effecting a photocycle based on light-driven formation and subsequent spontaneous decay of a flavin-cysteinyl adduct. Here we report that VVD presents alternative outcomes to light exposure that result in protein self-oxidation and, unexpectedly, rise of stability through kinetic control. Using optical absorbance and mass spectrometry we show that purified VVD develops amorphous aggregates with the presence of oxidized residues located at the cofactor binding pocket. Light exposure increases oxidative levels in VVD and specific probe analysis identifies singlet oxygen production by the flavin. These results indicate that VVD acts alternatively as a photosensitizer, inducing self-oxidative damage and subsequent aggregation. Surprisingly, BL illumination has an additional, opposite effect in VVD. We show that light-induced adduct formation establishes a stable state, delaying protein aggregation until photoadduct decay occurs. In accordance, repeated BL illumination suppresses VVD aggregation altogether. Furthermore, photoadduct formation confers VVD stability against chemical denaturation. Analysis of the aggregation kinetics and testing of stabilizers against aggregation reveal that aggregation in VVD proceeds through light-dependent kinetic control and dimer formation. These results uncover the aggregation pathway of a photosensor, where light induces a remarkable interplay between protein damage and stability."

Article

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS CIENCIAS TECNOLÓGICAS

Trichoderma as a model to study effector-like molecules

CLAUDIA ADRIANA RAMIREZ VALDESPINO J Sergio Casas Flores VIANEY GRACIELA OLMEDO MONFIL (2019)

"Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant-microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them."

Article

Trichoderma Effector molecules Plant-microbe interactions Secondary metabolites Effector proteins Small RNA BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA MICROBIOLOGÍA MICROBIOLOGÍA

Community of thermoacidophilic and arsenic resistant microorganisms isolated from a deep profile of mine heaps

J SERGIO CASAS FLORES ELIDA YAZMIN GOMEZ RODRIGUEZ JESSICA VIRIDIANA GARCIA MEZA (2015)

"Soluble arsenic (As) in acidic feed solution may inhibit the copper (Cu) bioleaching process within mine heaps. To clarify the effect of soluble arsenic on the live biomass and bioxidative activity in heaps, toxicological assays were performed using a synthetic feed solution given by a mine company. The microorganisms had previously been isolated from two heap samples at up to 66 m depth, and cultured using specific media for chemolithotrophic acidophiles (pH 1-2) and moderate thermophiles (48 degrees C), for arsenic tolerance assay. The four media with the highest biomass were selected to assay As-resistance; one culture (Q63h) was chosen to assay biooxidative activity, using a heap sample that contained chalcopyrite and covellite. We found that 0.5 g/L of As does not affect living biomass or biooxidative activity on Cu sulfides, but it dissolves Cu, while As precipitates as arsenic acid (H3AsO4 center dot 1/2H(2)O). The arsenic tolerant community, as identified by 16S rDNA gene sequence analysis, was composed of three main metabolic groups: chemolithotrophs (Leptospirillum, Sulfobacillus); chemolithoheterotrophs and organoheterotrophs as Acidovorax temperans, Pseudomonas alcaligenes, P. mendocina and Sphingomonas spp. Leptospirillum spp. and S. thermosulfidooxidans were the dominant taxa in the Q63-66 cultures from the deepest sample of the oldest, highest-temperature heap. The results indicated arsenic resistance in the microbial community, therefore specific primers were used to amplify ars (arsenic resistance system), aio (arsenite oxidase), or arr (arsenate respiratory reduction) genes from total sample DNA. Presence of arsB genes in S. thermosulfidooxidans in the Q63-66 cultures permits H3AsO4-As(V) detoxification and strengthens the community's response to As."

Article

Mine heaps Bacterial diversity Extremophiles Arsenic resistance system BIOLOGÍA Y QUÍMICA

Thermophile mats of microalgae growing on the woody structure of a cooling tower of a thermoelectric power plant in Central Mexico

Matas de microalgas termófilas que crecen sobre la estructura de madera de una torre de enfriamiento de una central termoeléctrica en el centro de México

YADIRALIA COVARRUBIAS RUBIO ENRIQUE ARTURO CANTORAL URIZA J SERGIO CASAS FLORES JESSICA VIRIDIANA GARCIA MEZA (2016)

"The aims of this research are to identify and describe a periphyton community of thermophilic microalgae in order to expand our knowledge on biodiversity of a particular environment. Conspicuous biomass of thermophilic microalgae (48 °C) inhabits the cooling towers of the thermoelectric power plant of Villa de Reyes (Central Mexico). Aggregate samples or microalgal mats were taken in three different areas of the top of a cooling tower, for identification. According to the sequencing analysis of 16S and 18S rDNA genes, the community is dominated by 3 species of Cyanoprokaryota: Chlorogloeopsis fritschii, Arthronema africanum and Chroococcidiopsis sp., previously reported as thermophiles. Also, 2 species of the Chlorophyte or green algae Scenedesmus. Finally, 12 species of diatoms comprise the microalgal community; diatoms were only microscopically identified within the mats, suggesting that the mats constitute a suitable microenvironment in thermal ambiences. The identified species are of particular interest because their habitat represents an extreme and an artificial biotope. To the best of our knowledge, this is the first report of thermophilic communities of microalgae in Mexico from a power plant; also, this is the first report of A. africanum for the country."

"Esta investigación tiene por objetivo identificar y describir la comunidad perifítica de microalgas termófilas, para expandir nuestro conocimiento de la biodiversidad en ambientes particulares, como las microalgas termófilas (48 °C) que crecen de manera conspicua en la zona superior de la torre de enfriamiento de la central termoeléctrica de Villa de Reyes (centro de México). Se tomaron muestras de agregados o tapetes microalgales en 3 zonas distintas de la parte superior de una torre de enfriamiento, para su identificación. Una vez realizada la amplificación, la clonación y el análisis de los genes que codifican para las subunidades 16S y 18S del rDNA, se observó el predominio de 3 especies de Cyanoprokaryota: Chlorogloeopsis fritschii, Arthronema africanum y Chroococcidiopsis sp., especies descritas como termófilas en trabajos previos. Además, se identificaron 2 especies de Chlorophyta (algas verdes) del género Scenedesmus y 12 especies de diatomeas; la identificación de diatomeas se realizó a partir de observaciones por microscopia electrónica de barrido. Característicamente, las diatomeas solo se observaron dentro los densos tapetes algales que se conforman, sugiriendo que estos tapetes constituyen un microambiente conveniente en ambientes térmicos. Las especies identificadas son de particular interés, ya que su hábitat representa un biotopo extremo y artificial. Por lo que sabemos, este trabajo constituye el primer registro de microalgas termófilas que habitan en torres de enfriamiento y Arthronema africanum se documenta por primera vez para México."

Article

Microalgal mats Thermophilic Arthronema africanum Diatoms BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA

Histone deacetylase HDA-2 regulates Trichoderma atroviride growth, conidiation, blue light perception, and oxidative stress responses

MACARIO OSORIO CONCEPCION GEMA ROSA CRISTOBAL MONDRAGON BRAULIO GUTIERREZ MEDINA J SERGIO CASAS FLORES (2017)

"Fungal blue-light photoreceptors have been proposed as integrators of light and oxidative stress. However, additional elements participating in the integrative pathway remain to be identified. In Trichoderma atroviride, the blue-light regulator (BLR) proteins BLR-1 and -2 are known to regulate gene transcription, mycelial growth, and asexual development upon illumination, and recent global transcriptional analysis revealed that the histone deacetylase-encoding gene hda-2 is induced by light. Here, by assessing responses to stimuli in wild-type and Δhda-2 backgrounds, we evaluate the role of HDA-2 in the regulation of genes responsive to light and oxidative stress. Δhda-2 strains present reduced growth, misregulation of the con-1 gene, and absence of conidia in response to light and mechanical injury. We found that the expression of hda-2 is BLR-1 dependent and HDA-2 in turn is essential for the transcription of early and late light-responsive genes that include blr-1, indicating a regulatory feedback loop. When subjected to reactive oxygen species (ROS), Δhda-2 mutants display high sensitivity whereas Δblr strains exhibit the opposite phenotype. Consistently, in the presence of ROS, ROS-related genes show high transcription levels in wild-type and Δblr strains but misregulation in Δhda-2 mutants. Finally, chromatin immunoprecipitations of histone H3 acetylated at Lys9/Lys14 on cat-3 and gst-1 promoters display low accumulation of H3K9K14ac in Δblr and Δhda-2 strains, suggesting indirect regulation of ROS-related genes by HDA-2. Our results point to a mutual dependence between HDA-2 and BLR proteins and reveal the role of these proteins in an intricate gene regulation landscape in response to blue light and ROS."

Article

Trichoderma Blue light Oxidative stress BLR proteins Histone acetylation Histone deacetylases HDA-2 Hos2p CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA