The physiological role of the unfolded protein response in plants

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602011000100010&lng=es&nrm=isoUnfolded protein response (UPR) is a signaling mechanism activated by misfolded protein accumulation in the endoplasmic reticulum. It is a widespread process that has been described in organisms ranging from yeasts to mammals. In recent years, our understanding of UPR signaling pathway in plants has advanced. Two transcription factors from Arabidopsis thaliana have been reported to function as the sensor/ transducer of this response (AtbZIP60 and AtbZIP28). They seem to be involved in both heat and biotic stress. Furthermore, overexpression of one of them (AtbZIP60) produces plants with a higher tolerance for salt stress, suggesting that this transcription factor may play a role in abiotic stress. Furthermore, some data suggest that crosstalk between genes involved in abiotic stress and UPR may also exist in plants. On the other hand, UPR is related to programmed cell death (PCD) in plants given that that triggering UPR results in induction of PCD-related genes. This article reviews the latest progress in understanding UPR signaling in plants and analyzes its relationship to key processes in plant physiology

Producción de un cortometraje sobre la cultura macabea del cantón Morona.

Se realizó la producción de un cortometraje sobre la Cultura Macabea del cantón Morona. Se inició con una minuciosa búsqueda de personas que, por su trayectoria en la ciudad de Macas, cuna de la Cultura Macabea, aportaron de manera significativa conocimientos y saberes fundamentales para el desarrollo de este cortometraje. Posteriormente, se realizó entrevistas a cada uno de los poseedores de saberes, información que fue recolectada y utilizada para el desarrollo de la parte técnica del cortometraje. Se realizó una investigación sobre el conocimiento actual de la cultura Macabea, para determinar si dicha cultura se encuentra en peligro de desaparecer o no. Con base en esta investigación, se procedió con el análisis técnico de cuál sería el tipo de cortometraje idóneo para poder transmitir de mejor manera los conocimientos recolectados. A continuación, se procedió con la elaboración del proyecto audiovisual, se realizó la preproducción del cortometraje, que consistió en la elaboración de los guiones técnico, literario y el storyboard. Además, se planificó el rodaje, tomando en cuenta todos los materiales e implementos necesarios para realizar de manera correcta la fase de producción, en esta fase se desarrollaron los guiones elaborados en la preproducción. Finalmente, se realizó la posproducción, que consistió en editar mediante el software de video ADOBE PREMIERE las escenas recaudadas en la fase de producción, agregar efectos, transiciones, audios, canciones además de correcciones de color y encuadre. Por último, se realizó la renderización del trabajo audiovisual, en el cual se determinaron los formatos y resoluciones adecuadas para su posterior difusión, ya sea en redes sociales como fue previsto o a través de medios como la televisión o cine. La difusión también se le realizará mediante instituciones como la Casa de la Cultura Núcleo de Morona Santiago, el Gobierno Municipal del cantón Morona y el gobierno provincial de Morona Santiago.The production of a short film about the Macabea Culture of Morona canton was carried out. It began with a meticulous search of people who, by their trajectory in Macas city, the cradle of the Macabea Culture, contributed in a significant way knowledge and fundamental knowledge for the development of this short film. Subsequently, interviews were held with each one of the possessors of knowledge, information that was collected and used for the development of the technical part of the short film. An investigation was carried out on the current knowledge of the Macabea culture, to determine, if said culture is in danger of disappearing or not. Based on this research, we proceeded with the technical analysis of what would be the ideal type of short film to be able to transmit the collected knowledge in a better way. Then, we proceeded with the development of the audiovisual project, the preproduction of the short film was made, which involved the elaboration of the technical, literary and storyboard scripts. Additionally, filming was planned, taking into account all the materials and implements necessary to correctly perform the production phase, in this phase the scripts elaborated in preproduction were developed. Following, the post-production was carried out, which consisted of editing the scenes collected in the production phase through ADOBE PREMIERE video software, adding effects, transitions, audios, songs as well as color corrections and framing. Lastly, the audiovisual work was rendered, in which the appropriate formats and resolutions were determined for their subsequent dissemination, either in social networks as planned or through media such as television or cinema. The dissemination will also be made through institutions such as the “Casa de la Cultura Núcleo Morona Santiago” and the Morona Municipal Government and the Morona Santiago Provincial Government

A Rapid and Efficient Method for Purifying High Quality Total RNA from Peaches (Prunus persica) for Functional Genomics Analyses

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000100010&lng=es&nrm=isoPrunus persica has been proposed as a genomic model for deciduous trees and the Rosaceae family. Optimized protocols for RNA isolation are necessary to further advance studies in this model species such that functional genomics analyses may be performed. Here we present an optimized protocol to rapidly and efficiently purify high quality total RNA from peach fruits (Prunus persica). Isolating high-quality RNA from fruit tissue is often difficult due to large quantities of polysaccharides and polyphenolic compounds that accumulate in this tissue and co-purify with the RNA. Here we demonstrate that a modified version of the method used to isolate RNA from pine trees and the woody plant Cinnamomun tenuipilum is ideal for isolating high quality RNA from the fruits of Prunus persica. This RNA may be used for many functional genomic based experiments such as RT-PCR and the construction of large-insert cDNA libraries

Functional Interchangeability of Nucleotide Sugar Transporters URGT1 and URGT2 Reveals That urgt1 and urgt2 Cell Wall Chemotypes Depend on Their Spatio-Temporal Expression

[EN] Nucleotide sugar transporters (NSTs) are Golgi-localized proteins that play a role in polysaccharide biosynthesis by transporting substrates (nucleotide sugars) from the cytosol into the Golgi apparatus. In Arabidopsis, there is an NST subfamily of six members, called URGTs, which transport UDP-rhamnose and UDP-galactose in vitro. URGTs are very similar in protein sequences, and among them, URGT1 and URGT2 are highly conserved in protein sequence and also showed very similar kinetic parameters toward UDP-rhamnose and UDP-galactose in vitro. Despite the similarity in sequence and in vitro function, mutants in urgt1 led to a specific reduction in galactose in rosette leaves. In contrast, mutants in urgt2 showed a decrease in rhamnose content in soluble mucilage from seeds. Given these specific and quite different chemotypes, we wonder whether the differences in gene expression could explain the observed differences between the mutants. Toward that end, we analyzed whether URGT2 could rescue the urgt1 phenotype and vice versa by performing a promoter swapping experiment. We analyzed whether the expression of the URGT2 coding sequence, controlled by the URGT1 promoter, could rescue the urgt1 rosette phenotype. A similar strategy was used to determine whether URGT1 could rescue the urgt2 mucilage phenotype. Expression analysis of the swapped genes, using qRT-PCR, was similar to the native URGT1 and URGT2 genes in wild-type plants. To monitor the protein expression of the swapped genes, both URGTs were tagged with green fluorescent protein (GFP). Confocal microscopy analyses of the swapped lines containing URGT2-GFP showed fluorescence in motile dot-like structures in rosette leaves. Swapped lines containing URGT1-GFP showed fluorescence in dot-like structures in the seed coat. Finally, the expression of URGT2 in urgt1 mutants rescued galactose reduction in rosette leaves. In the same manner, the expression of URGT1 in urgt2 mutants recovered the content of rhamnose in soluble mucilage. Hence, our results showed that their expression in different organs modulates the role in vivo of URGT1 and URGT2. Likely, this is due to their presence in different cellular contexts, where other proteins, acting in partnership, may drive their functions toward different pathways.SIThis work was supported by FONDECYT 11160787 and 1204467 (SS-A), 1151335 (AO), and 3170796 (AL-G), FONDAP- Centro de Regulación del Genoma 15090007 (AO), ECOSud-CONICYT C14B02 (AO), and PAI 79170136 (SS-A)

Identification of Novel Components of the Unfolded Protein Response in Arabidopsis

Unfavorable environmental and developmental conditions may cause disturbances in protein folding in the endoplasmic reticulum (ER) that are recognized and counteracted by components of the Unfolded Protein Response (UPR) signaling pathways. The early cellular responses include transcriptional changes to increase the folding and processing capacity of the ER. In this study, we systematically screened a collection of inducible transgenic Arabidopsis plants expressing a library of transcription factors for resistance toward UPR-inducing chemicals. We identified 23 candidate genes that may function as novel regulators of the UPR and of which only three genes (bZIP10, TBF1, and NF-YB3) were previously associated with the UPR. The putative role of identified candidate genes in the UPR signaling is supported by favorable expression patterns in both developmental and stress transcriptional analyses. We demonstrated that WRKY75 is a genuine regulator of the ER-stress cellular responses as its expression was found to be directly responding to ER stress-inducing chemicals. In addition, transgenic Arabidopsis plants expressing WRKY75 showed resistance toward salt stress, connecting abiotic and ER-stress responses

The Root Hair Specific SYP123 Regulates the Localization of Cell Wall Components and Contributes to Rizhobacterial Priming of Induced Systemic Resistance

Indexación: Web of Science.Root hairs are important for nutrient and water uptake and are also critically involved the interaction with soil inhabiting microbiota. Root hairs are tubular-shaped outgrowths that emerge from trichoblasts. This polarized elongation is maintained and regulated by a robust mechanism involving the endomembrane secretory and endocytic system. Members of the syntaxin family of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) in plants (SYP), have been implicated in regulation of the fusion of vesicles with the target membranes in both exocytic and endocytic pathways. One member of this family. SYP123, is expressed specifically in the root hairs and accumulated in the growing tip region. This study shows evidence of the SYP123 role in polarized trafficking using knockout insertional mutant plants. We were able to observe defects in the deposition of cell wall proline rich protein PRP3 and cell wall polysaccharides. In a complementary strategy, similar results were obtained using a plant expressing a dominant negative soluble version of SYP123 (SP2 fragment) lacking the transmembrane domain. The evidence presented indicates that SYP123 is also regulating PRP3 protein distribution by recycling by endocytosis. We also present evidence that indicates that SYP123 is necessary for the response of roots to plant growth promoting rhizobacterium (PGPR) in order to trigger trigger induced systemic response (ISR). Plants with a defective SYP123 function were unable to mount a systemic acquired resistance in response to bacterial pathogen infection and ISR upon interaction with rhizobacteria. These results indicated that SYP123 was involved in the polarized localization of protein and polysaccharides in growing root hairs and that this activity also contributed to the establishment of effective plant defense responses. Root hairs represent very plastic structures were many biotic and abiotic factors can affect the number, anatomy and physiology of root hairs. Here, we presented evidence that indicates that interactions with soil PGPR could be closely regulated by signaling involving secretory and/or endocytic trafficking at the root hair tip as a quick way to response to changing environmental conditions.http://journal.frontiersin.org/article/10.3389/fpls.2016.01081/ful

The <i>Arabidopsis</i> Golgi-localized GDP-L-fucose transporter is required for plant development

Indexación: Web of Science.Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development.http://www.nature.com/articles/ncomms1211

Responsabilidad del auditor externo en la evaluación del control interno relevante para la prevención del lavado de dinero y de activos en las empresas importadoras y comercializadoras de arroz asociadas a ASALBAR.

En la actualidad el fenómeno delictivo denominado “Lavado de Dinero” está entre los acontecimientos más impactantes en materia de política criminal, el cual se define como cualquier operación, transacción, acción u omisión encaminada a ocultar el origen ilícito y a legalizar bienes y valores provenientes de actividades delictivas cometidas dentro o fuera del país. La profesión de contaduría pública ha evolucionado notablemente debido a la demanda de los servicios que este rubro ofrece, esto ha inducido a la superación y especialización de dicha profesión para garantizar la prestación efectiva de los servicios, razón por la cual, se debe contar con los conocimientos y destrezas adecuadas para su ejecución. Como auditor, la responsabilidad es factor clave, ya que, se debe cumplir con los requisitos de control de calidad que la normativa técnica exige, sin embargo, el auditor debe dar fe pública para dictaminar los estados financieros, proporcionando así, un valor agregado a la profesión. Por lo tanto, el objetivo de la investigación fue la elaboración de un cuestionario enfocado a evaluar el control interno de la entidad, en materia de prevención de lavado de dinero y de activos, que facilite al auditor externo el cumplimiento de la resolución 12/2016 emitida por el CVPCPA. La investigación se realizó bajo el enfoque cualitativo puesto que se seleccionaron a los auditores externos que auditan las empresas comercializadoras de arroz asociadas a ASALBAR, el modelo de la investigación se realizó bajo el método hipotético-deductivo, aplicando las diferentes fases como la observación, la formulación de hipótesis y la deducción. Para la recopilación de la información se utilizó la entrevista, la cual nos permitió conocer el efecto del problema estudiado sobre las unidades de análisis