Polynuclear Cu4I4py4 complex loaded in mesoporous silica: Photophysics, theoretical investigation, and highly sensitive oxygen sensing application

The polynuclear Cu4I4py4 complex has been largely studied in solution and in the powder form due to its interesting luminescent properties, which are largely dependent on temperature and pressure. In this work, we present the synthesis of the complex and its wet impregnation in a mesoporous silica host obtained by sol-gel methodology. For optimized guest loadings, the well-dispersed guest molecules exhibit strong interaction with molecular oxygen, resulting in a significant quenching of the luminescence. The process is highly reversible with a Stern-Volmer constant of Ksv = 33.8, which is the largest value found in the literature for similar complexes in the solid state, suggesting that the new material is a promising candidate for high sensitivity oxygen sensing. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations reveal a weak intermolecular interaction between two guest complexes in the excited state, suggesting the formation of an excited state complex (excimer). The assumption of triplet excimer formation is confirmed by temperature- and concentration-dependent experiments, which provides a new way to explain the giant Stokes shift observed for the guest complex in different media

The Origins and Historical Assembly of the Brazilian Caatinga Seasonally Dry Tropical Forests

This is the final version. Available on open access from Frontiers Media via the DOI in this recordData Availability Statement: The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/Supplementary Material.The Brazilian Caatinga is considered the richest nucleus of the Seasonally Dry Tropical Forests (SDTF) in the Neotropics, also exhibiting high levels of endemism, but the timing of origin and the evolutionary causes of its plant diversification are still poorly understood. In this study, we integrate comprehensive sampled dated molecular phylogenies of multiple flowering plant groups and estimations of ancestral areas to elucidate the forces driving diversification and historical assembly in the Caatinga flowering plants. Our results show a pervasive floristic exchange between Caatinga and other neotropical regions, particularly those adjacent. While some Caatinga lineages arose in the Eocene/Oligocene, most dry-adapted endemic plant lineages found in region emerged from the middle to late Miocene until the Pleistocene, indicating that only during this period the Caatinga started to coalesce into a SDTF like we see today. Our findings are temporally congruent with global and regional aridification events and extensive denudation of thick layers of sediments in Northeast (NE) Brazil. We hypothesize that global aridification processes have played important role in the ancient plant assembly and long-term Caatinga SDTF biome stability, whereas climate-induced vegetation shifts, as well as the newly opened habitats have largely contributed as drivers of in situ diversification in the region. Patterns of phylogenetic relatedness of Caatinga endemic clades revealed that much modern species diversity has originated in situ and likely evolved via recent (Pliocene/Pleistocene) ecological specialization triggered by increased environmental heterogeneity and the exhumation of edaphically disparate substrates. The continuous assembly of dry-adapted flora of the Caatinga has been complex, adding to growing evidence that the origins and historical assembly of the distinct SDTF patches are idiosyncratic across the Neotropics, driven not just by continental-scale processes but also by unique features of regional-scale geological history

Mapping the root systems of individual trees in a natural community using genotyping-by-sequencing

•The architecture of root systems is an important driver of plant fitness, competition and ecosystem processes. However, the methodological difficulty of mapping roots hampers the study of these processes. Existing approaches to match individual plants to belowground samples are low throughput and species specific. Here, we developed a scalable sequencing-based method to map the root systems of individual trees across multiple species. We successfully applied it to a tropical dry forest community in the Brazilian Caatinga containing 14 species. • We sequenced all 42 individual shrubs and trees in a 14 × 14 m plot using double-digest restriction site-associated sequencing (ddRADseq). We identified species-specific markers and individual-specific haplotypes from the data. We matched these markers to the ddRADseq data from 100 mixed root samples from across the centre (10 × 10 m) of the plot at four different depths using a newly developed R package. • We identified individual root samples for all species and all but one individual. There was a strong significant correlation between belowground and aboveground size measurements, and we also detected significant species-level root-depth preference for two species. • The method is more scalable and less labour intensive than the current techniques and is broadly applicable to ecology, forestry and agricultural biology

DNA Sequence Variation among Conspecific Accessions of the Legume Coursetia caribaea Reveals Geographically Localized Clades Here Ranked as Species

 This is the author accepted manuscript. The final version is available from ASPT via the DOI in this recordCoursetia caribaea is geographically and morphologically the most variable species in the genus Coursetia and in the tribe Robinieae (Leguminosae, Papilionoideae). Because of potentially undetected species, we assessed the phylogenetic relationships among the eight taxonomic varieties of C. caribaea. Sampling included nuclear ribosomal internal transcribed spacer sequences from 489 Robinieae accessions representing all varieties of C. caribaea and 38 of the 40 species of Coursetia, in addition to chloroplast trnD-trnT sequences from 186 accessions. Separate and combined phylogenetic analyses resolved a clade of conspecific accessions of the Bolivian C. caribaea var. astragalina as sister to the central Andean Coursetia grandiflora clade. Also distantly related to Coursetia caribaea var. caribaea accessions were those of the coastal Oaxacan C. caribaea var. pacifica, which formed the sister clade to accessions of the central Andean C. caribaea var. ochroleuca. The estimated mean ages of the stem clades for these three lineages, 11, 7.7, and 7.7 Ma, respectively, contrasted to the estimated mean ages of the corresponding crown clades of 0, 0, and 1.5 Ma. The contrasting stem and crown ages suggest that these taxa, appropriately ranked as species, Coursetia astragalina , Coursetia diversifolia , and Coursetia ochroleuca , each have persisted over evolutionary time frames as distinct geographically localized populations in seasonally dry tropical forests and woodlands.USDA National Institute of Food and Agricultur

Mapping the root systems of individual trees in a natural community using genotyping-by-sequencing.

This is the final version. Available from Wiley via the DOI in this record.The architecture of root systems is an important driver of plant fitness, competition and ecosystem processes. However, the methodological difficulty of mapping roots hampers the study of these processes. Existing approaches to match individual plants to belowground samples are low throughput and species specific. Here, we developed a scalable sequencing-based method to map the root systems of individual trees across multiple species. We successfully applied it to a tropical dry forest community in the Brazilian Caatinga containing 14 species. We sequenced all 42 individual shrubs and trees in a 14 × 14 m plot using double-digest restriction site-associated sequencing (ddRADseq). We identified species-specific markers and individual-specific haplotypes from the data. We matched these markers to the ddRADseq data from 100 mixed root samples from across the centre (10 × 10 m) of the plot at four different depths using a newly developed R package. We identified individual root samples for all species and all but one individual. There was a strong significant correlation between belowground and aboveground size measurements, and we also detected significant species-level root-depth preference for two species. The method is more scalable and less labour intensive than the current techniques and is broadly applicable to ecology, forestry and agricultural biology.Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Fundação de Amparo à Pesquisa do Estado de São Paul

Application of Chinese Jun-Cao technique for the production of Brazilian Ganoderma lucidum strains

Ganoderma lucidum is a medicinal mushroom traditionally used in China against a wide range of diseases such as cancer and also for its prevention. In this work, commercial Chinese strains G. lucidum were compared to wild Brazilian strains aiming to determine the cultivation potential through the use of Jun-Cao. Six formulations were tested and the strains presented good response to the applied method. In general, the mixture between the grass and wood was well suited for the basidiomycetes, contributing to the preparation of substrates that generated better results in Jun Cao