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Las pipas para fumar encontradas en contextos arqueológicos demuestran que los pueblos indígenas del Noroeste Pacífico de Norteamérica han fumado desde hace 4,500 años. La arqueometría y la metabolómica de residuos antiguos arrojan evidencia para la asociación de ciertas plantas con estos artefactos. En este artículo, sintetizamos investigaciones recientes y presentamos el estado de conocimiento acerca de la distribución espacial y temporal de la práctica del fumar en el pasado. La presencia de pipas de fumar, hechas de piedras, en el registro arqueológico se junta con nuestro entendimiento del uso de plantas en el pasado basado en análisis de residuos químicos para así crear un panorama de las prácticas de fumar antes del Contacto europeo. Los datos de pipas arqueológicas demuestran que el fumar fue una práctica ampliamente distribuida en la región interior del Noroeste a lo largo de varios miles de años, pero que esto no fue así en la costa. Datos de distribución—incluyendo evidencia positiva y negativa de estudios de residuos químicos—señalan que el tabaco fue una planta de fumar importante en la región ya hace cerca de 1,410 años y tan al norte como la zona intermedia del río Columbia. La metabolómica de residuos antiguos contribuye a un entendimiento más copioso del uso de plantas específicas en el pasado a través de la identificación de especies de tabaco y otras plantas indígenas, incluyendo Rhus glabra, Cornus sericia y Salvia sp., como contribuyentes de los residuos químicos en pipas antiguas. 

A particular type of miniature ceramic vessel locally known as “veneneras” is occasionally found during archaeological excavations in the Maya Area. To date, only one study of a collection of such containers successfully identified organic residues through coupled chromatography–mass spectrometry methods. That study identified traces of nicotine likely associated with tobacco. Here we present a more complete picture by analyzing a suite of possible complementary ingredients in tobacco mixtures across a collection of 14 miniature vessels. The collection includes four different vessel forms and allows for the comparison of specimens which had previously formed part of museum exhibitions with recently excavated, untreated containers. Archaeological samples were compared with fresh as well as cured reference materials from two different species of tobacco (Nicotiana tabacumandN. rustica). In addition, we sampled six more plants which are linked to mind-altering practices through Mesoamerican ethnohistoric or ethnographic records. Analyses were conducted using UPLC-MS metabolomics-based analytical techniques, which significantly expand the possible detection of chemical compounds compared to previous biomarker-focused studies. Results include the detection of more than 9000 residual chemical features. We trace, for the first time, the presence of Mexican marigold (Tagetes lucida) in presumptive polydrug mixtures.

 

Plants live in association with microorganisms that positively influence plant development, vigor, and fitness in response to pathogens and abiotic stressors. The bulk of the plant microbiome is concentrated belowground at the plant root-soil interface. Plant roots secrete carbon-rich rhizodeposits containing primary and secondary low molecular weight metabolites, lysates, and mucilages. These exudates provide nutrients for soil microorganisms and modulate their affinity to host plants, but molecular details of this process are largely unresolved. We addressed this gap by focusing on the molecular dialog between eight well-characterized beneficial strains of the Pseudomonas fluorescens group and Brachypodium distachyon , a model for economically important food, feed, forage, and biomass crops of the grass family. We collected and analyzed root exudates of B. distachyon and demonstrated the presence of multiple carbohydrates, amino acids, organic acids, and phenolic compounds. The subsequent screening of bacteria by Biolog Phenotype MicroArrays revealed that many of these metabolites provide carbon and energy for the Pseudomonas strains. RNA-seq profiling of bacterial cultures amended with root exudates revealed changes in the expression of genes encoding numerous catabolic and anabolic enzymes, transporters, transcriptional regulators, stress response, and conserved hypothetical proteins. Almost half of the differentially expressed genes mapped to the variable part of the strains’ pangenome, reflecting the importance of the variable gene content in the adaptation of P. fluorescens to the rhizosphere lifestyle. Our results collectively reveal the diversity of cellular pathways and physiological responses underlying the establishment of mutualistic interactions between these beneficial rhizobacteria and their plant hosts.