Disease and Healing in Ancient Societies: Dental Calculus Residues and Skeletal Pathology Data Indicate Age and Sex-Biased Medicinal Practices among Native Californians

The health of humans is intricately linked to the substances - both food and non-dietary items -we ingest. Adverse health outcomes related to smoking of products like tobacco and other psychoactive substances are clearly established in modern populations but are less well understood for ancient communities. Grasping these dynamics is further complicated by the curative, religious, and medicinal context of many of these substances, which have often been commodified, refined, and altered in recent history. As part of a larger collaboration with the Muwekma Ohlone Tribe dedicated to understanding medicinal plant use among native Californians, we present a summary of new metabolomic data from three Middle and Late-period ancestral heritage Ohlone sites: Thámien Rúmmeytak (CA-SCL-128), ’Ayttakiš ’Éete Hiramwiš Trépam-tak (CA-ALA-677/H/H), and Sii Tuupentak (CA-ALA-565/H/H). Using a UPLC-MS platform, we analyze chemical residues from 95 human dental calculus samples from 50 burials. Employing multivariate statistics, we co-analyzed demographic and skeletal pathology data with chemical residue profiles. We considered skeletal markers for a series of oral and postcranial health conditions. Results indicate sex and age biases in consumption patterns. Periodontitis stands out as the most significant local factor for changes in the oral metabolome. However, while chemical markers of oral diseases may be related to pathogen activity, associations between residues and postcranial conditions such as osteoarthritis suggest traditional curative practices and the ingestion of medicinal substances. Hence, our study yields new insights into the broader context of illness and healing in the past

Disease and Healing in Ancient Societies: Dental Calculus Residues and Skeletal Pathology Data Indicate Age- and Sex-Biased Medicinal Practices among Native Californians

The health of humans is intricately linked to the substances we ingest—both food and nondietary items. Adverse health outcomes related to smoking of such products as tobacco and other psychoactive substances are clearly established in modern populations but are less well understood for ancient communities. Grasping these dynamics is further complicated by the curative, religious, and medicinal context of many of these substances, which have often been commodified, refined, and altered in recent history. As part of a larger collaboration with the Muwekma Ohlone Tribe dedicated to understanding medicinal plant use among Native Californians, this article summarizes new metabolomic data from three Middle- and Late-Period ancestral heritage Ohlone sites: Thámien Rúmmeytak (CA-SCL-128), ’Ayttakiš ’Éete Hiramwiš Trépam-tak (CA-ALA-677/H), and Síi Túupentak (CA-ALA-565/H). The authors used an ultra-performance liquid chromatography-mass spectrometry platform to analyze chemical residues from 95 human dental calculus samples from 50 burials. Using multivariate statistics, they coanalyzed demographic and skeletal pathology data with chemical residue profiles and considered skeletal markers for a series of oral and postcranial health conditions. Results indicate sex and age biases in consumption patterns. Periodontitis stands out as the most significant local factor for changes in the oral metabolome. However, while chemical markers of oral diseases may be related to pathogen activity, associations between residues and postcranial conditions such as osteoarthritis suggest traditional curative practices and the ingestion of medicinal substances. Hence, this study yields new insights into the broader context of illness and healing in the past

Root Exudates Alter the Expression of Diverse Metabolic, Transport, Regulatory, and Stress Response Genes In Rhizosphere \u3ci\u3ePseudomonas\u3c/i\u3e

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

Database of Arabidopsis Metabolites

Bacterial infection of crops is a major concern for farmers. Depending on the crop, yield losses can be significant. Management of bacterial disease requires applying antibiotic and copper chemical sprays, breeding for disease resistance, and inducing systematic acquired resistance, a type of whole plant immunity. Research using the model plant Arabidopsis has provided insights into plant-microbe interactions. The knowledge gained from researching Arabidopsis can be applied to crops. However, incomplete databases have limited the capabilities of identifying new signaling metabolites that set the basal defense state of Arabidopsis so that these plants can reduce bacterial infections. Analytical and natural products chemistry techniques in combination with omics-based methods are necessary for characterizing a larger suite of bioactive metabolites

The Roles of a Flavone-6-Hydroxylase and 7-O-Demethylation in the Flavone Biosynthetic Network of Sweet Basil

Background: Late steps of lipophilic flavone biosynthesis in mints are unknown. Results: CYP82D monooxygenases catalyze 6-hydroxylation of 7- O -methylated precursor, whose 7-methyl group is subsequently removed by demethylation in basil but not in peppermint. Conclusion: Flavone biosynthesis in basil involves an unusual loop. Significance: Novel mechanisms elucidated in basil suggest a new hypothesis for similar metabolic networks in other plants. Lipophilic flavonoids found in the Lamiaceae exhibit unusual 6- and 8-hydroxylations whose enzymatic basis is unknown. We show that crude protein extracts from peltate trichomes of sweet basil ( Ocimum basilicum L.) cultivars readily hydroxylate position 6 of 7- O -methylated apigenin but not apigenin itself. The responsible protein was identified as a P450 monooxygenase from the CYP82 family, a family not previously reported to be involved in flavonoid metabolism. This enzyme prefers flavones but also accepts flavanones in vitro and requires a 5-hydroxyl in addition to a 7-methoxyl residue on the substrate. A peppermint ( Mentha × piperita L.) homolog displayed identical substrate requirements, suggesting that early 7- O -methylation of flavones might be common in the Lamiaceae. This hypothesis is further substantiated by the pioneering discovery of 2-oxoglutarate-dependent flavone demethylase activity in basil, which explains the accumulation of 7- O -demethylated flavone nevadensin

Accumulation of Salicylic Acid and Related Metabolites in <i>Selaginella moellendorffii</i>

Salicylic acid (SA) is a phytohormone that plays manifold roles in plant growth, defense, and other aspects of plant physiology. The concentration of free SA in plants is fine-tuned by a variety of structural modifications. SA is produced by all land plants, yet it is not known whether its metabolism is conserved in all lineages. Selaginella moellendorffii is a lycophyte and thus a representative of an ancient clade of vascular plants. Here, we evaluated the accumulation of SA and related metabolites in aerial parts of S. moellendorffii. We found that SA is primarily stored as the 2-O-β-glucoside. Hydroxylated derivatives of SA are also produced by S. moellendorffii and stored as β-glycosides. A candidate signal for SA aspartate was also detected. Phenylpropanoic acids also occur in S. moellendorffii tissue. Only o-coumaric acid is stored as the β-glycoside, while caffeic, p-coumaric, and ferulic acids accumulate as alkali-labile conjugates. An in silico search for enzymes involved in conjugation and catabolism of SA in the S. moellendorffii genome indicated that experimental characterization is necessary to clarify the physiological functions of the putative orthologs. This study sheds light on SA metabolism in an ancestral plant species and suggests directions towards elucidating the underlying mechanisms

A Set of Regioselective O

Polymethoxylated flavonoids occur in a number of plant families, including the Lamiaceae. To date, the metabolic pathways giving rise to the diversity of these compounds have not been studied. Analysis of our expressed sequence tag database for four sweet basil (Ocimum basilicum) lines afforded identification of candidate flavonoid O-methyltransferase genes. Recombinant proteins displayed distinct substrate preferences and product specificities that can account for all detected 7-/6-/4′-methylated, 8-unsubstituted flavones. Their biochemical specialization revealed only certain metabolic routes to be highly favorable and therefore likely in vivo. Flavonoid O-methyltransferases catalyzing 4′- and 6-O-methylations shared high identity (approximately 90%), indicating that subtle sequence changes led to functional differentiation. Structure homology modeling suggested the involvement of several amino acid residues in defining the proteins’ stringent regioselectivities. The roles of these individual residues were confirmed by site-directed mutagenesis, revealing two discrete mechanisms as a basis for the switch between 6- and 4′-O-methylation of two different substrates. These findings delineate major pathways in a large segment of the flavone metabolic network and provide a foundation for its further elucidation

A set of regioselective O-methyltransferases gives rise to the complex pattern of methoxylated flavones in sweet basil

Polymethoxylated flavonoids occur in a number of plant families, including the Lamiaceae. To date, the metabolic pathways giving rise to the diversity of these compounds have not been studied. Analysis of our expressed sequence tag database for four sweet basil (Ocimum basilicum) lines afforded identification of candidate flavonoid O-methyltransferase genes. Recombinant proteins displayed distinct substrate preferences and product specificities that can account for all detected 7-/6-/4'-methylated, 8-unsubstituted flavones. Their biochemical specialization revealed only certain metabolic routes to be highly favorable and therefore likely in vivo. Flavonoid O-methyltransferases catalyzing 4'- and 6-O-methylations shared high identity (approximately 90%), indicating that subtle sequence changes led to functional differentiation. Structure homology modeling suggested the involvement of several amino acid residues in defining the proteins' stringent regioselectivities. The roles of these individual residues were confirmed by site-directed mutagenesis, revealing two discrete mechanisms as a basis for the switch between 6- and 4'-O-methylation of two different substrates. These findings delineate major pathways in a large segment of the flavone metabolic network and provide a foundation for its further elucidation

Rootstock and Crop Load Effects on ‘Honeycrisp’ Photosynthetic Performance and Carbohydrate Accumulation

Rootstock selection and crop load adjustment are key practices in apple orchard management; nevertheless, the effects of rootstocks and crop load levels on important physiological processes of the scions, such as photosynthetic performance and carbohydrate accumulation, are still unclear. To investigate the impact of different rootstocks and crop load levels on scion photosynthesis and carbohydrate buildup, in 2020, ‘Honeycrisp’ trees grafted on rootstocks ‘G.41’, ‘G.935’, and ‘M.9-T337’ were thinned to low and high crop load levels, and photosynthetic performance and carbohydrate accumulation in leaves and fruit were evaluated. Leaves from ‘G.935’ showed the highest net photosynthesis and electron use efficiency of photosynthesis and the lowest activity for non-net carboxylative processes, all together indicative of enhanced photosynthetic performance. High crop load determined an increase in gas exchange, suggesting a positive feedback of high fruit competition on carbon assimilation. While rootstock ‘M.9-T337’ showed a higher accumulation of starch in leaves, no pattern regarding the composition of leaf-soluble sugars among rootstocks could be identified. Conversely, by the end of the harvest season, leaves from low-cropping trees had higher fructose, glucose, and sorbitol than those from high-cropping trees, but differences in starch content were not significant. Fructose and sorbitol concentrations were affected by rootstock and crop load, respectively. Overall, this study showed that high cropping enhanced photosynthesis in ‘Honeycrisp’ apple and determined lower accumulation of some soluble carbohydrates (fructose, glucose, sorbitol) in leaves. This study also provided insights into how rootstocks affect photosynthetic performance of ‘Honeycrisp’, highlighting ‘G.935’ as the rootstock conferring the highest photosynthetic capacity under the present experimental conditions

Organic Farming Sharpens Plant Defenses in the Field

Plants deploy a variety of chemical and physical defenses to protect themselves against herbivores and pathogens. Organic farming seeks to enhance these responses by improving soil quality, ultimately altering bottom up regulation of plant defenses. While laboratory studies suggest this approach is effective, it remains unclear whether organic agriculture encourages more-active plant defenses under real-world conditions. Working on the farms of cooperating growers, we examined gene expression in the leaves of two potato (Solanum tuberosum) varieties, grown on organic vs. conventional farms. For one variety, Norkotah, we found significantly heightened initiation of genes associated with plant-defense pathways in plants grown in organic vs. conventional fields. Organic Norkotah fields exhibited lower levels of nitrate in soil and of nitrogen in plant foliage, alongside differences in communities of soil bacteria, suggesting possible links between soil management and observed differences in plant defenses. Additionally, numbers of predatory and phloem-feeding insects were higher in organic than conventional fields. A second potato variety, Alturas, which is generally grown using fewer inputs and in poorer-quality soils, exhibited lower overall herbivore and predator numbers, few differences in soil ecology, and no differences in gene-activity in organic and conventional farming systems. Altogether, our results suggest that organic farming has the potential to increase plants' resistance to herbivores, possibly facilitating reduced need for insecticide applications. These benefits appear to be mediated by plant variety and/or farming context