Genomic history of coastal societies from eastern South America

Sambaqui (shellmound) societies are among the most intriguing archaeological phenomena in pre-colonial South America, extending from approximately 8,000 to 1,000 years before present (yr bp) across 3,000 km on the Atlantic coast. However, little is known about their connection to early Holocene hunter-gatherers, how this may have contributed to different historical pathways and the processes through which late Holocene ceramists came to rule the coast shortly before European contact. To contribute to our understanding of the population history of indigenous societies on the eastern coast of South America, we produced genome-wide data from 34 ancient individuals as early as 10,000 yr bp from four different regions in Brazil. Early Holocene hunter-gatherers were found to lack shared genetic drift among themselves and with later populations from eastern South America, suggesting that they derived from a common radiation and did not contribute substantially to later coastal groups. Our analyses show genetic heterogeneity among contemporaneous Sambaqui groups from the southeastern and southern Brazilian coast, contrary to the similarity expressed in the archaeological record. The complex history of intercultural contact between inland horticulturists and coastal populations becomes genetically evident during the final horizon of Sambaqui societies, from around 2,200 yr bp, corroborating evidence of cultural change

From funerary taphonomy to mortuary practices: a case study of the archaeological site Caixa d\'Água (Buritizeiro - MG)

As práticas mortuárias dos grupos humanos que habitaram o Brasil Central, durante o Holoceno médio, ainda são amplamente desconhecidas pela Arqueologia Brasileira, devido à escassez de sítios deste período. O sítio arqueológico Caixa D\'água, localizado às margens do Rio São Francisco, no município de Buritizeiro (MG), é uma importante exceção, pois apresenta dezenas de esqueletos putativamente datados do Holoceno médio. No presente trabalho este material foi estudado sob a perspectiva da Tafonomia Funerária. Os esqueletos foram curados e diagnosticados para sexo e idade a partir de marcadores osteológicos. Um banco de dados em formato de matriz binária com as informações registradas em campo e em laboratório dos sepultamentos foi elaborado. As informações foram interpretadas a partir da visão da Tafonomia Funerária. Esses dados foram analisados através de estatísticas multivariadas para a identificação de padrões funerários. Com esses resultados em mãos, foi investigada a correlação entre organização funerária e a cultura material associada aos esqueletos.The mortuary practices of the human groups that inhabited Central Brazil, during the middle Holocene, are still largely unknown by Brazilian Archeology, due to the scarcity of sites from this period. The Caixa D\'água archaeological site, located on the banks of the São Francisco River, in the municipality of Buritizeiro (MG), is an important exception, as it has dozens of skeletons putatively dated to the middle Holocene. In the present work, this material was studied from the perspective of Funerary Taphonomy. Skeletons were diagnosed for sex and age using osteological markers. A database in binary matrix format with the information recorded in the field and in the laboratory of the burials was created. The information was interpreted from the point of view of Funerary Taphonomy. These data were analyzed using multivariate statistics to identify funerary patterns. The correlation between funerary organization and the material culture associated with skeletons was investigated

Hypoxia-driven Changes In Glycolytic And Tricarboxylic Acid Cycle Metabolites Of Two Nodulated Soybean Genotypes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Oxygen deprivation triggers changes at different levels of carbon and nitrogen metabolism, which may differ between plant-genotypes. The aim of this study was to evaluate the hypoxia-induced alterations of carbon and nitrogen metabolites in relation to alanine aminotransferase (AlaAT; EC 2.6.1.2) activity in two genotypes of nodulated soybean (Glycine max). Nodulated soybean plants (Fundacep 53 RR and BRS Macota) were grown in vermiculite and transferred to a hydroponic system at the early reproductive stage. The root system was subjected to hypoxia by continuously flushing the solution with N-2 gas for 24 or 72 h. For recovery, after 72 h in hypoxia, plants returned to normoxic conditions after transfer to vermiculite for 24 and 72 h. Root and nodule organic acids and amino acids were analysed by gas chromatography-mass spectrometry and high-performance liquid chromatography, respectively. Relative expression of AlaAT and AIaAT activity were also verified in both genotypes. Plants of Fundacep and Macota genotypes responded distinctly to hypoxia. In root tissues, Fundacep presented higher pyruvate and lactate accumulation than Macota, indicating higher glycolytic and fermentation rates. Furthermore, Fundacep responded more effectively on recovery by restoring pre-hypoxic levels of the metabolites. Although the amino acid composition did not differ between the genotypes, there was a clear link between glycolysis and the Krebs-cycle via increased gene expression and activity of AIaAT allied to succinate accumulation in roots of Fundacep. This may represents a metabolic advantage for this genotype over Macota with regard to hypoxia tolerance. (C) 2016 Elsevier B.V. All rights reserved.133118127Empresa Brasileira de Pesquisa Agropecuaria (Embrapa)MonsantoCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Waterlogging-induced changes in fermentative metabolism in roots and nodules of soybean genotypes

Waterlogging blocks the oxygen supply to the root system which inhibits respiration, and greatly reduces the energy status of cells that affect important metabolic processes. This study evaluated fermentative metabolism and carbohydrate contents in the root system of two soybean (Glycine max L. Merril) genotypes under hypoxic and post-hypoxic conditions. Nodulated plants (genotypes Fundacep 53 RR and BRS Macota) were grown in vermiculite and transferred to a hydroponic system at the reproductive stage. The root system was submitted to hypoxia by flowing N2 (nitrogen) gas in a solution for 24 and 72 h. For recovery, plants returned to normoxia condition by transfer to vermiculite for 24 and 72 h. Fermentative enzyme activity, levels of anaerobic metabolites and carbohydrate content were all quantified in roots and nodules. The activity of alcohol dehydrogenase, pyruvate decarboxylase and lactate dehydrogenase enzymes, as well as the content of ethanol and lactate, increased with hypoxia in roots and nodules, and subsequently returned to pre-hypoxic levels in the recovery phase in both genotypes. Pyruvate content increased in nodules and decreased in roots. Sugar and sucrose levels increased in roots and decreased in nodules under hypoxia in both genotypes. Fundacep RR 53 was more responsive to the metabolic effects caused by hypoxia and post-hypoxia than BRS Macota, and it is likely that these characteristics contribute positively to improving adaptation to oxygen deficiency

Nitrogen source influences the antioxidative system of soybean plants under hypoxia and re-oxygenation

In this work, we compared nitrate-supplied plants (non-nodulated) with non-nitratesupplied plants (nodulated) under oxygen privation of root system (hypoxia) and re-oxygenation (post-hypoxia; recovery) in order to verify whether N sources affect the antioxidant system during oxidative stress caused by hypoxia and post-hypoxia conditions. Antioxidant enzymatic activities, ascorbate redox state, and reactive oxygen species (ROS) levels were analyzed in roots and leaves of two soybean genotypes, Fundacep 53 RR and BRS Macota at reproductive stage R2, during hypoxia and post-hypoxia in an experiment carried out in a hydroponic system. The antioxidant system was strongly induced in roots of nitrate-supplied plants of both genotypes, with high activity of superoxide dismutase, ascorbate peroxidase, catalase, glutathione reductase and guayacol peroxidase. It also increased reduced ascorbate and ascorbate redox state and decreased ROS production under hypoxia and recovery, while in leaves of nodulated and non-nodulated plants, a slight increase on antioxidant system was observed. Nitrate may benefit soybean plants under hypoxic conditions and subsequent re-oxygenation by inducing the antioxidant system mainly in roots to cope with ROS production and reduce oxidative damage

Nitrogen source influences the antioxidative system of soybean plants under hypoxia and re-oxygenation

ABSTRACT: In this work, we compared nitrate-supplied plants (non-nodulated) with non-nitrate-supplied plants (nodulated) under oxygen privation of root system (hypoxia) and re-oxygenation (post-hypoxia; recovery) in order to verify whether N sources affect the antioxidant system during oxidative stress caused by hypoxia and post-hypoxia conditions. Antioxidant enzymatic activities, ascorbate redox state, and reactive oxygen species (ROS) levels were analyzed in roots and leaves of two soybean genotypes, Fundacep 53 RR and BRS Macota at reproductive stage R2, during hypoxia and post-hypoxia in an experiment carried out in a hydroponic system. The antioxidant system was strongly induced in roots of nitrate-supplied plants of both genotypes, with high activity of superoxide dismutase, ascorbate peroxidase, catalase, glutathione reductase and guayacol peroxidase. It also increased reduced ascorbate and ascorbate redox state and decreased ROS production under hypoxia and recovery, while in leaves of nodulated and non-nodulated plants, a slight increase on antioxidant system was observed. Nitrate may benefit soybean plants under hypoxic conditions and subsequent re-oxygenation by inducing the antioxidant system mainly in roots to cope with ROS production and reduce oxidative damage

Root-hypoxia tolerance in soybean sister-lines plants indicates a better balance in energy use/dissipation and oxidative stress control

Climatic changes are leading to an increased number of flooding year by year which impacts negatively the metabolism of roots and influences the shoot metabolism which leads to a decline in soybean productivity. This can be more drastic when it is cultivated in lowland soils. Our group hypothesized that tolerant sister-line plants have more capacity to cope with oxidative stress due to better management of energy use and dissipation on photosynthesis machinery during root-flooding and recovery conditions, while in sensitive soybean sister-line the impairment of the photosynthetic use and dissipation of energy lead to an unbalanced redox state response. For that, soybean seeds from the same parents, PELBR15- 7015C (flooding tolerant) and PELBR15-7060 (flooding sensitive) were sowed and cultivated in 500 L capacity plastic containers with lowland soil simulating the field management process. At the reproductive stage, the roots were subjected to flooding for 11 days, then drained to analyze reoxygenation (3 d) and recovery (10 d). Tolerant plants have a greater ability to manage root flooding conditions compared to sensitive ones. The ability includes efficient energy use and dissipation, which minimizes the production of reactive oxygen species (ROS) and subsequent cell damage. Conversely, in sensitive sister lines, impaired electron transport chains lead to increased ROS production and damage. Upon reoxygenation and recovery, the tolerant sister lines exhibit a faster metabolism turnover, allowing them to cope more effectively with the stress on leaves and roots. While both sister lines are capable of detoxifying ROS, the tolerant sister line's superior ability to manage energy use and dissipation allows for more stable and rapid control of oxidative stress