Expansive evolution of the TREHALOSE-6-PHOSPHATE PHOSPHATASE gene family in Arabidopsis

Trehalose is a nonreducing sugar used as a reserve carbohydrate and stress protectant in a variety of organisms. While higher plants typically do not accumulate high levels of trehalose, they encode large families of putative trehalose biosynthesis genes. Trehalose biosynthesis in plants involves a two-step reaction in which trehalose-6-phosphate (T6P) is synthesized from UDPglucose and glucose-6-phosphate (catalyzed by T6P synthase [TPS]), and subsequently dephosphorylated to produce the disaccharide trehalose (catalyzed by T6P phosphatase [TPP]). In Arabidopsis (Arabidopsis thaliana), 11 genes encode proteins with both TPS- and TPP-like domains but only one of these (AtTPS1) appears to be an active (TPS) enzyme. In addition, plants contain a large family of smaller proteins with a conserved TPP domain. Here, we present an in-depth analysis of the 10 TPP genes and gene products in Arabidopsis (TPPA-TPPJ). Collinearity analysis revealed that all of these genes originate from whole-genome duplication events. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that all encode active TPP enzymes with an essential role for some conserved residues in the catalytic domain. These results suggest that the TPP genes function in the regulation of T6P levels, with T6P emerging as a novel key regulator of growth and development in higher plants. Extensive gene expression analyses using a complete set of promoter-beta-glucuronidase/green fluorescent protein reporter lines further uncovered cell- and tissue-specific expression patterns, conferring spatiotemporal control of trehalose metabolism. Consistently, phenotypic characterization of knockdown and overexpression lines of a single TPP, AtTPPG, points to unique properties of individual TPPs in Arabidopsis, and underlines the intimate connection between trehalose metabolism and abscisic acid signaling

Musgos cultivados, indicadores ambientales de contaminación atmosférica

La contaminación atmosférica se ha asociado a diversas enfermedades respiratorias y cardiovasculares (Pan et al., 2015; Yang et al., 2015; Zhang et al., 2015). Es por ello que hoy en día la calidad del aire es un tema de gran interés, tanto en el aspecto ambiental como de salud (Zarazúa et al., 2013). Sin embargo, el monitoreo convencional de los contaminantes atmosféricos no siempre es posible debido a los costos generados por la adquisición y mantenimiento de los equipos tecnológicos necesarios (Ares et al., 2012; Barandovski et al.,2015). Para contrarrestar esta situación, se tiene como alternativa el uso de organismo biológicos como biomonitores de los contaminantes (Malizia et al., 2012; Salo, 2014;Stankovic et al., 2014).Los musgos han demostrado ser muy útiles como bioindicadores de la contaminación del aire. El presente trabajo representa una alternativa a los tipos de monitoreo tradicionales (pasivo y activo), ya que propone evitar la extracción del musgo nativo de los sitios de monitoreo; en su lugar plantea el cultivo in vitro del musgo y su posterior exposición en los sitios de monitoreo. El protocolo incluye la identificación de la especie, obtención del esporofito con la cápsula cerrada, la esterilización de la cápsula de esporas con una solución de NaClO. Posteriormente la cápsula se rompe y se liberan las esporas en agua estéril, para ser dispersadas en medio BCD para su cultivo. La incubación de las esporas ocurre a temperatura e intensidad de luz controlada, condiciones que se mantienen constantes hasta que la planta produce gametofitos. Por este método se asegura la obtención de musgo no contaminado para su posterior exposición a la contaminación atmosférica. El biomonitoreo resulta ser un método relativamente económico y fácil de implementar, por lo que es una alternativa viable para ser desarrollada en lugares en donde no se cuente con la infraestructura para monitorear la calidad del aire.Universidad Autónoma del Estado de México - CONACY

Presence of flower thrips Frankliniella schultzei in ornamental plants

Objective: to report the presence of Frankliniella schultzei in geranium (Pelargonium hortorum) and vinca (Catharanthus roseus) plants, in greenhouses in the State of Morelos, Mexico. Design/methodology/approach: geranium and vinca plants were sampled in greenhouses located in the Municipality of Jojutla, Morelos, Mexico. The collected specimens were brown to dark brown color, were processed and mounted on glass slides and identified by means of taxonomic keys and the use of a conventional microscope. Results: the specimens collected in geranium and vinca presented morphological characteristics corresponding to the species Frankliniella schultei. Limitations on study/implications: monitoring of the species is necessary now that its presence is known in at least two areas of Mexico: the west and center of the country. Findings/conclusions: in Mexico, Frankliniella schultzei had only been reported in the west, with this report it is now known that it is also located in the central part of the country.Objective: To report on the presence of Frankliniella schultzei in geranium (Pelargonium hortorum) and periwinkle (Catharanthus roseus) plants in greenhouses in the State of Morelos, Mexico. Design/Methodology/Approach: We sampled geranium and periwinkle plants in greenhouses in the municipality of Jojutla, Morelos, Mexico. The collected specimens—of light to dark brown color—were processed, mounted on glass slides to be observed through a conventional light microscope, and identified with taxonomic keys. Results: The specimens collected in the geranium and periwinkle plants presented morphological traits that conform to the species Frankliniella schultzei. Study limitations/Implications: Monitoring the species is necessary because its presence has been identified in at least two regions of Mexico: West and Center. Findings/Conclusions: Frankliniella schultzei had only been located in western Mexico. This report shows that the species is also found in the central region of the country

Effect of externally added trehalose on the growth and sugar partitioning in Physcomitrella patens

status: publishe