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The diversity of life on Earth is a result of continual innovations in molecular networks influencing morphology and physiology. Plant specialized metabolism produces hundreds of thousands of compounds, offering striking examples of these innovations. To understand how this novelty is generated, we investigated the evolution of the Solanaceae family-specific, trichome-localized acylsugar biosynthetic pathway using a combination of mass spectrometry, RNA-seq, enzyme assays, RNAi and phylogenomics in different non-model species. Our results reveal hundreds of acylsugars produced across the Solanaceae family and even within a single plant, built on simple sugar cores. The relatively short biosynthetic pathway experienced repeated cycles of innovation over the last 100 million years that include gene duplication and divergence, gene loss, evolution of substrate preference and promiscuity. This study provides mechanistic insights into the emergence of plant chemical novelty, and offers a template for investigating the ~300,000 non-model plant species that remain underexplored. There are about 300,000 species of plant on Earth, which together produce over a million different small molecules called metabolites. Plants use many of these molecules to grow, to communicate with each other or to defend themselves against pests and disease. Humans have co-opted many of the same molecules as well; for example, some are important nutrients while others are active ingredients in medicines. Many plant metabolites are found in almost all plants, but hundreds of thousands of them are more specialized and only found in small groups of related plant species. These specialized metabolites have a wide variety of structures, and are made by different enzymes working together to carry out a series of biochemical reactions. Acylsugars are an example of a group of specialized metabolites with particularly diverse structures. These small molecules are restricted to plants in the Solanaceae family, which includes tomato and tobacco plants. Moghe et al. have now focused on acylsugars to better understand how plants produce the large diversity of chemical structures found in specialized metabolites, and how these processes have evolved over time. An analysis of over 35 plant species from across the Solanaceae family revealed hundreds of acylsugars, with some plants accumulating 300 or more different types of these specialized metabolites. Moghe et al. then looked at the enzymes that make acylsugars from a poorly studied flowering plant called Salpiglossis sinuata, partly because it produces a large diversity of these small molecules and partly because it sits in a unique position in the Solanaceae family tree. The activities of the enzymes were confirmed both in test tubes and in plants. This suggested that many of the enzymes were “promiscuous”, meaning that they could likely use a variety of molecules as starting points for their chemical reactions. This finding could help to explain how this plant species can make such a wide variety of acylsugars. Moghe et al. also discovered that many of the enzymes that make acylsugars are encoded by genes that were originally copies of other genes and that have subsequently evolved new activities. Plant scientists and plant breeders value tomato plants that produce acylsugars because these natural chemicals protect against pests like whiteflies and spider mites. A clearer understanding of the diversity of acylsugars in the Solanaceae family, as well as the enzymes that make these specialized metabolites, could help efforts to breed crops that are more resistant to pests. Some of the enzymes related to those involved in acylsugar production could also help to make chemicals with pharmaceutical value. These new findings might also eventually lead to innovative ways to produce these chemicals on a large scale.

Identifying traits that affect rates of speciation and extinction and, hence, explain differences in species diversity among clades is a major goal of evolutionary biology. Detecting such traits is especially difficult when they undergo frequent transitions between states. Self-incompatibility, the ability of hermaphrodites to enforce outcrossing, is frequently lost in flowering plants, enabling self-fertilization. We show, however, that in the nightshade plant family (Solanaceae), species with functional self-incompatibility diversify at a significantly higher rate than those without it. The apparent short-term advantages of potentially self-fertilizing individuals are therefore offset by strong species selection, which favors obligate outcrossing.

Background The Solanaceae is a plant family of great economic importance. Despite a wealth of phylogenetic work on individual clades and a deep knowledge of particular cultivated species such as tomato and potato, a robust evolutionary framework with a dated molecular phylogeny for the family is still lacking. Here we investigate molecular divergence times for Solanaceae using a densely-sampled species-level phylogeny. We also review the fossil record of the family to derive robust calibration points, and estimate a chronogram using an uncorrelated relaxed molecular clock. Results Our densely-sampled phylogeny shows strong support for all previously identified clades of Solanaceae and strongly supported relationships between the major clades, particularly within Solanum . The Tomato clade is shown to be sister to section Petota, and the Regmandra clade is the first branching member of the Potato clade. The minimum age estimates for major splits within the family provided here correspond well with results from previous studies, indicating splits between tomato & potato around 8 Million years ago (Ma) with a 95% highest posterior density (HPD) 7–10 Ma, Solanum & Capsicum c. 19 Ma (95% HPD 17–21), and Solanum & Nicotiana c. 24 Ma (95% HPD 23–26). Conclusions Our large time-calibrated phylogeny provides a significant step towards completing a fully sampled species-level phylogeny for Solanaceae, and provides age estimates for the whole family. The chronogram now includes 40% of known species and all but two monotypic genera, and is one of the best sampled angiosperm family phylogenies both in terms of taxon sampling and resolution published thus far. The increased resolution in the chronogram combined with the large increase in species sampling will provide much needed data for the examination of many biological questions using Solanaceae as a model system.

Steroidal alkaloids play a crucial role in plant defense and exhibit distinct stereochemistry at C25, forming either the tomato-type (25 S ) or eggplant-type (25 R ) isomers. Here, we uncover the molecular mechanisms shaping this stereochemical diversity. Phylogenetic analysis of GLYCOALKALOID METABOLISM 8 ( GAME8 ) cytochrome P450 hydroxylases across the Solanaceae family revealed two distinct clades producing either 25 S or 25 R isomers. Ancestral GAME8 likely favored 25 R , with gene duplications giving rise to 25 S -producing enzymes in more recent Solanum species. In S. nigrum and S. dulcamara , multiple GAME8 copies generate mixed isomeric profiles. Notably, in wild S. cheesmaniae from the Galápagos, mutations in GAME8 have driven a shift from 25 S back to the ancestral 25 R , suggesting reverse evolution. Our findings highlight how GAME8 evolution has shaped alkaloid diversity in the genus Solanum , demonstrating a complex interplay between enzyme function, genetic variation, and evolutionary adaptation. Researchers uncover how plants control the stereochemistry of steroidal alkaloids, key compounds in defense. They show that evolution of GAME8 enzymes in Solanum species has shaped alkaloid diversity, including cases of reverse evolution in wild tomatoes.

Anatabine is a minor tobacco alkaloid, which is also found in plants of the Solanaceae family and displays a chemical structure similarity with nicotine. We have shown previously that anatabine displays some anti-inflammatory properties and reduces microgliosis and tau phosphorylation in a pure mouse model of tauopathy. We therefore investigated the effects of a chronic oral treatment with anatabine in a transgenic mouse model (Tg PS1/APPswe) of Alzheimer's disease (AD) which displays pathological A beta deposits, neuroinflammation and behavioral deficits. In the elevated plus maze, Tg PS1/APPswe mice exhibited hyperactivity and disinhibition compared to wild-type mice. Six and a half months of chronic oral anatabine treatment, suppressed hyperactivity and disinhibition in Tg PS1/APPswe mice compared to Tg PS1/APPswe receiving regular drinking water. Tg PS1/APPswe mice also elicited profound social interaction and social memory deficits, which were both alleviated by the anatabine treatment. We found that anatabine reduces the activation of STAT3 and NF Kappa B in the vicinity of A beta deposits in Tg PS1/APPswe mice resulting in a reduction of the expression of some of their target genes including Bace1, iNOS and Cox-2. In addition, a significant reduction in microgliosis and pathological deposition of A beta was observed in the brain of Tg PS1/APPswe mice treated with anatabine. This is the first study to investigate the impact of chronic anatabine treatment on AD-like pathology and behavior in a transgenic mouse model of AD. Overall, our data show that anatabine reduces beta -amyloidosis, neuroinflammation and alleviates some behavioral deficits in Tg PS1/APPswe, supporting further exploration of anatabine as a possible disease modifying agent for the treatment of AD.

Tropane alkaloids (TAs) are widely distributed in the Solanaceae, while some important medicinal tropane alkaloids (mTAs), such as hyoscyamine and scopolamine, are restricted to certain species/tribes in this family. Little is known about the genomic basis and evolution of TAs biosynthesis and specialization in the Solanaceae. Here, we present chromosome-level genomes of two representative mTAs-producing species: Atropa belladonna and Datura stramonium . Our results reveal that the two species employ a conserved biosynthetic pathway to produce mTAs despite being distantly related within the nightshade family. A conserved gene cluster combined with gene duplication underlies the wide distribution of TAs in this family. We also provide evidence that branching genes leading to mTAs likely have evolved in early ancestral Solanaceae species but have been lost in most of the lineages, with A. belladonna and D. stramonium being exceptions. Furthermore, we identify a cytochrome P450 that modifies hyoscyamine into norhyoscyamine. Our results provide a genomic basis for evolutionary insights into the biosynthesis of TAs in the Solanaceae and will be useful for biotechnological production of mTAs via synthetic biology approaches. Tropane alkaloids (TAs) are synthesized by some species in Solanaceae. Here, the authors assemble the genomes of two representative TAs producing species, show that gene loss shapes uneven distribution of TAs in Solanaceae, and identify a cytochrome P450 gene catalyzing N -demethylation of hyoscyamine to generate norhyoscyamine.

Small RNAs are key regulators in plant growth and development. One subclass, phased siRNAs (phasiRNAs) require a trigger microRNA for their biogenesis. In grasses, two pathways yield abundant phasiRNAs during anther development; miR2275 triggers one class, 24-nt phasiRNAs, coincident with meiosis, while a second class of 21-nt phasiRNAs are present in premeiotic anthers. Here we report that the 24-nt phasiRNA pathway is widely present in flowering plants, indicating that 24-nt reproductive phasiRNAs likely originated with the evolutionary emergence of anthers. Deep comparative genomic analyses demonstrated that this miR2275/24-nt phasiRNA pathway is widely present in eudicots plants, however, it is absent in legumes and in the model plant Arabidopsis, demonstrating a dynamic evolutionary history of this pathway. In Solanaceae species, 24-nt phasiRNAs were observed, but the miR2275 trigger is missing and some loci displaying 12-nt phasing. Both the miR2275-triggered and Solanaceae 24-nt phasiRNAs are enriched in meiotic stages, implicating these phasiRNAs in anther and/or pollen development, a spatiotemporal pattern consistent in all angiosperm lineages that deploy them. 24-nt phased siRNA (phasiRNA) regulate reproduction in grasses, yet are absent from Arabidopsis , and were thought to be monocot-specific. Here, Xia et al. show that 24-nt phasiRNAs are in fact broadly distributed among eudicots and are consistently enriched during meiosis, despite possibly arising from distinct biogenesis pathways.

Ethnobotanical field surveys were carried out in the Tanawal area of the Lesser Himalayan Region, Khyber Pakhtunkhawa, Province from April 2016 to October 2017. The area is located between 34.36 (34° 21’ 30 N) latitude and 73.07 (73° 4’ 0 E) longitude with an average elevation of 1374 meters above sea level. Ethnomedicinal data were collected through Participatory Rural Appraisal (PRA), and participants were selected through the snow-boll technique. Semi-structured, in-depth and open-ended interviews were conducted. The data were quantitatively evaluated using ethnomedicinal indices i.e. Relative frequency of citation (RFCs), Fidelity level (FL), and Use Value (UV). The ethnobotanical data were also comparatively analyzed through the Jaccard Index (JI). The study yielded 66 medicinal plants in 62 genera and 43 families. Asteraceae and Solanaceae were the most important families with five medicinal taxa each. Regarding medicinal plant part utilization, leaves (43.28%) were used predominantly, followed by whole plant (14.92%) and fruits (14.92%). Decoction was the main drug formulation applied to 21 species (31.15%) and the oral route was most common (56.1%) while 31.2% of medicinal plants were used for both oral and topical applications. Fifty health disorders were recorded and grouped in 15 categories. Maximum species were used to treat gastrointestinal disorders i.e. 13 species, dermal problems (12 species), and respiratory tract ailments (9). The calculated RFCs ranged between 81 to 31. The most important medicinal plants were Acacia modesta , Citrullus vulgaris , Tamarindus indica , and Momordica charantia with an RGFC of 81 each. The UV ranged between 0.58 and 3.6. Medicinal taxa with the highest UV were Dioscorea deltoidea (3.6), Withania coagulans (3.3), Momordica charantia (3.5), Silybum marianum and Pyrus pashia (3.2). FL values showed that 28 (41.79%) species had a FL value below 50 (74.62%) while 39 (58.20%) had higher FL values. Momordica charantia , Tamarindus indica , Acacia modesta and Citrullus vulgaris were 95.2 each. The Jaccard Index (JI) values ranged from16.77 to 0.98. The current study also reported 16 medicinal plants, commonly used around the globe, have been rarely documented for their medicinal values in the local ethnomedicinal literature i.e. Althaea officinalis , Plantanus orientalis , Jasminum sombac , Maytenus royleana , Cucurbita maxima , Phyllanthus emblica , Citrullus vulgaris . Polygonatum verticilliatum , Caseria tomentosa , Cistanche tubulosa , Bambusa arundinacea , Schinus molle , Tamarindus indica , Pongamia pinnata , Citrus limon and Catharanthus roseus . However, 48 medicinal plants had been reported in the literature but the current study reported their novel medicinal uses. Important taxa should be established in botanical gardens for in-situ conservation, chemical investigation and sustainable utilization. It would also be effective to improve the livelihoods of the local population.

Four new species of Capsicum (Capsiceae, Solanaceae) from Andean tropical forests in South America are described. Capsicum benoistii Hunz. ex Barboza sp. nov. (incertae sedis) is endemic to a restricted area in south-central Ecuador and is most similar to the more widespread C. geminifolium (Dammer) Hunz. (Colombia, Ecuador, and Peru). Capsicum piuranum Barboza & S. Leiva sp. nov. (Andean clade) is found in northern Peru (Department Piura) and is morphologically most similar to C. caballeroi M. Nee of the Bolivian yungas (Departments Santa Cruz and Cochabamba) but closely related to C. geminifolium and C. lycianthoides Bitter. Capsicum longifolium Barboza & S. Leiva sp. nov. (Andean clade) occurs from northern Peru (Departments Amazonas, Cajamarca, and Piura) to southern Ecuador (Province Zamora-Chinchipe), and is morphologically most similar to C. dimorphum (Miers) Kuntze (Colombia, Ecuador, and Peru). Capsicum neei Barboza & X. Reyes sp. nov. (Bolivian clade) is endemic to southeastern Bolivia (Departments Chuquisaca and Santa Cruz) in the Boliviano-Tucumano Forest, is morphologically most similar to another Bolivian endemic species C. minutiflorum Rusby (Hunz.), and is closely related to C. caballeroi. Complete descriptions, illustrations, distributions and conservation assessments of all new species are given. Chromosome numbers for C. piuranum and C. longifolium are also provided. Three of the new species were included in a new phylogenetic analysis for Capsicum; their positions were strongly resolved within clades previously recognized in the genus.