Science Enabled by Specimen Data

Liu, H., X. Feng, Y. Zhao, G. Lv, C. Zhang, Aruhan, T.-A. Damba, et al. 2024. Pharmacophylogenetic relationships of genus Dracocephalum and its related genera based on multifaceted analysis. Frontiers in Pharmacology 15. https://doi.org/10.3389/fphar.2024.1449426

The Lamiaceae genus Dracocephalum, with over 30 species, is believed to have considerable medicinal properties and is widely used in Eurasian ethnomedicine. Numerous studies have researched on the geographical distribution, metabolite identification, and bioactivity of Dracocephalum species, especially amidst debates concerning the taxonomy of its closely related genera Hyssopus and Lallemantia. These discussions present an opportunity for pharmacophylogenetic studies of these medicinal plants. In this review, we collated extensive literature and data to present a multifaceted view of the geographical distribution, phylogenetics, phytometabolites and chemodiversity, ethnopharmacological uses, and pharmacological activities of Dracocephalum, Hyssopus, and Lallemantia. We found that these genera were concentrated in Europe, with species adapted to various climatic zones. These genera shared close phylogenetic relationships, with Dracocephalum and Hyssopus displaying intertwined patterns in the phylogenetic tree. Our review assessed more than 900 metabolites from these three genera, with terpenoids and flavonoids being the most abundant. Researchers have recently identified novel metabolites within Dracocephalum, expanding our understanding of its chemical constituents. Ethnopharmacologically, these genera have been traditionally used for treating respiratory, liver and gall bladder diseases. Extracts and metabolites from these genera exhibit a range of pharmacological activities such as hepatoprotective, anti-inflammation, antimicrobial action, anti-hyperlipidaemia, and anti-tumour properties. By integrating phylogenetic analyses with network pharmacology, we explored the intrinsic links between metabolite profiles, traditional efficacy, and modern pharmacology of Dracocephalum and its related genera. This study contributes to the discovery of potential medicinal value from closely related species of Dracocephalum and aids in the development and sustainable use of medicinal plant resources.

Calleja-Satrustegui, A., A. Echeverría, I. Ariz, J. Peralta de Andrés, and E. M. González. 2024. Unlocking nature’s drought resilience: a focus on the parsimonious root phenotype and specialised root metabolism in wild Medicago populations. Plant and Soil. https://doi.org/10.1007/s11104-024-06943-w

Abstract  Background and aims Crop wild relatives, exposed to strong natural selection, exhibit effective tolerance traits against stresses. While an aggressive root proliferation phenotype has long been considered advantageous for a range of stresses, it appears to be counterproductive under drought due to its high metabolic cost. Recently, a parsimonious root phenotype, metabolically more efficient, has been suggested to be better adapted to semiarid environments, although it is not clear that this phenotype is a trait exhibited by crop wild relatives. Methods Firstly, we analysed the root phenotype and carbon metabolism in four Medicago crop wild relatives adapted to a semiarid environment and compared them with the cultivated M. truncatula Jemalong (A17). Secondly, we exposed the cultivated (probably the least adapted genotype to aridity) and the wild (the most common one in arid zones) M. truncatula genotypes to water deficit. The carbon metabolism response in different parts of their roots was analysed. Results A reduced carbon investment per unit of root length was a common trait in the four wild genotypes, indicative of an evolution towards a parsimonious root phenotype. During the water deficit experiment, the wild M. truncatula showed higher tolerance to drought, along with a superior ability of its taproot to partition sucrose and enhanced capacity of its fibrous roots to maintain sugar homeostasis. Conclusion A parsimonious root phenotype and the spatial specialization of root carbon metabolism represent two important drought tolerance traits. This work provides relevant findings to understand the response of Medicago species roots to water deficit.

Bradshaw, C. D., D. L. Hemming, T. Mona, W. Thurston, M. K. Seier, D. P. Hodson, J. W. Smith, et al. 2024. Transmission pathways for the stem rust pathogen into Central and East Asia and the role of the alternate host, barberry. Environmental Research Letters 19: 114097. https://doi.org/10.1088/1748-9326/ad7ee3

Abstract After many decades of effective control of stem rust caused by the Puccinia graminis f.sp. tritici, (hereafter Pgt) the reported emergence of race TTKSK/Ug99 of Pgt in Uganda reignited concerns about epidemics worldwide because ∼90% of world wheat cultivars had no resistance to the new race. Since it was initially detected in Uganda in 1998, Ug99 variants have now been identified in thirteen countries in Africa and the Middle East. Stem rust has been a major problem in the past, and concern is increasing about the risk of return to Central and East Asia. Whilst control programs in North America and Europe relied on the use of resistant cultivars in combination with eradication of barberry (Berberis spp.), the alternate host required for the stem rust pathogen to complete its full lifecycle, the focus in East Asia was principally on the use of resistant wheat cultivars. Here, we investigate potential airborne transmission pathways for stem rust outbreaks in the Middle East to reach East Asia using an integrated modelling framework combining estimates of fungal spore deposition from an atmospheric dispersion model, environmental suitability for spore germination, and crop calendar information. We consider the role of mountain ranges in restricting transmission pathways, and we incorporate a representation of a generic barberry species into the lifecycle. We find viable transmission pathways to East Asia from the Middle East to the north via Central Asia and to the south via South Asia and that an initial infection in the Middle East could persist in East Asia for up to three years due to the presence of the alternate host. Our results indicate the need for further assessment of barberry species distributions in East Asia and appropriate methods for targeted surveillance and mitigation strategies should stem rust incidence increase in the Middle East region.

Xu, L., Z. Song, T. Li, Z. Jin, B. Zhang, S. Du, S. Liao, et al. 2024. New insights into the phylogeny and infrageneric taxonomy of Saussurea based on hybrid capture phylogenomics (Hyb-Seq). Plant Diversity. https://doi.org/10.1016/j.pld.2024.10.003

Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae, comprising approximately 520 species from the Northern Hemisphere. A comprehensive infrageneric classification, supported by robust phylogenetic trees and corroborated by morphological and other data, has not yet been published. For the first time, we recovered a well-resolved nuclear phylogeny of Saussurea consisting of four main clades, which was also supported by morphological data. Our analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear conflict in Saussurea, and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of Saussurea. Based on the nuclear phylogeny obtained and morphological characters, we proposed a revised infrageneric taxonomy of Saussurea, which includes four subgenera and 13 sections. Specifically, 1) S. sect. Cincta, S. sect. Gymnocline, S. sect. Lagurostemon, and S. sect. Strictae were moved from S. subg. Saussurea to S. subg. Amphilaena, 2) S. sect. Pseudoeriocoryne was moved from S. subg. Eriocoryne to S. subg. Amphilaena, and 3) S. sect. Laguranthera was moved from S. subg. Saussurea to S. subg. Theodorea.

Kosch, T. A., A. J. Crawford, R. Lockridge Mueller, K. C. Wollenberg Valero, M. L. Power, A. Rodríguez, L. A. O’Connell, et al. 2024. Comparative analysis of amphibian genomes: An emerging resource for basic and applied research. Molecular Ecology Resources. https://doi.org/10.1111/1755-0998.14025

Amphibians are the most threatened group of vertebrates and are in dire need of conservation intervention to ensure their continued survival. They exhibit unique features including a high diversity of reproductive strategies, permeable and specialized skin capable of producing toxins and antimicrobial compounds, multiple genetic mechanisms of sex determination and in some lineages, the ability to regenerate limbs and organs. Although genomic approaches would shed light on these unique traits and aid conservation, sequencing and assembly of amphibian genomes has lagged behind other taxa due to their comparatively large genome sizes. Fortunately, the development of long‐read sequencing technologies and initiatives has led to a recent burst of new amphibian genome assemblies. Although growing, the field of amphibian genomics suffers from the lack of annotation resources, tools for working with challenging genomes and lack of high‐quality assemblies in multiple clades of amphibians. Here, we analyse 51 publicly available amphibian genomes to evaluate their usefulness for functional genomics research. We report considerable variation in genome assembly quality and completeness and report some of the highest transposable element and repeat contents of any vertebrate. Additionally, we detected an association between transposable element content and climatic variables. Our analysis provides evidence of conserved genome synteny despite the long divergence times of this group, but we also highlight inconsistencies in chromosome naming and orientation across genome assemblies. We discuss sequencing gaps in the phylogeny and suggest key targets for future sequencing endeavours. Finally, we propose increased investment in amphibian genomics research to promote their conservation.

Marchuk, E. A., A. K. Kvitchenko, L. A. Kameneva, A. A. Yuferova, and D. E. Kislov. 2024. East Asian forest-steppe outpost in the Khanka Lowland (Russia) and its conservation. Journal of Plant Research 137: 997–1018. https://doi.org/10.1007/s10265-024-01570-z

The Khanka Lowland forest-steppe is the most eastern outpost of the Eurasian steppe biome. It includes unique grassland plant communities with rare steppe species. These coenosis have changed under the influence of anthropogenic activity, especially during the last 100 years and included both typical steppe species and nemoral mesophytic species. To distinguish these ecological groups of plants the random forest method with three datasets of environmental variables was applied. Specifically, a model of classification with the most important bioindices to predict a mesophytic ecological group of plants with a sensitivity greater than 80% was constructed. The data demonstrated the presence of steppe species that arrived at different times in the Primorye Territory. Most of these species are associated with the Mongolian-Daurian relict steppe complex and habit in the Khanka Lowland. Other species occur only in mountains in Primorye Territory and do not persist in the Khanka Lowland. These findings emphasize the presence of relict steppe communities with a complex of true steppe species in the Khanka Lowland. Steppe communities exhibit features of anthropogenic influence definitely through the long land use period but are not anthropogenic in origin. The most steppe species are located at the eastern border of distribution in the Khanka Lowlands and are valuable in terms of conservation and sources of information about steppe species origin and the emergence of the steppe biome as a whole.

Amin, H., and A. Borzée. 2024. Understanding the Distribution, Behavioural Ecology, and Conservation Status of Asian Pelophylax. Diversity 16: 259. https://doi.org/10.3390/d16050259

Understanding species from an ecological and phylogenetic perspective facilitates an understanding of their conservation status in relation to the changing world. The frog genus Pelophylax is among the largest in terms of amphibian biomass in the Palearctic, but species have not been thoroughly studied at the Asian continental scale. The phylogeographic relationship, behavioural ecology, and ecological requirements within the genus need clarification, despite generally good local coverage. Here, for the first time, we conducted a literature review focused on phylogeography and behavioural ecology, supported by ecological niche modelling of twelve Asian Pelophylax lineages. Finally, we compiled the known threats for each of the lineages. We first determined the presence of twelve species and species-candidate lineages. In terms of behavioural ecology, the main difference among lineages is the time to metamorphosis and the time to reach sexual maturity. The ecological models highlighted a match between the known presence of each clade and their suitable habitat and highlighted the Syr Darya drainage on the eastern shore of the Caspian Sea for the non-described Pelophylax “Syr Darya lineage”. Finally, we highlighted the greatest variation among lineages in terms of threats, as some lineages are threatened by numerous factors, whereas others are expanding.

Cousins-Westerberg, R., N. Dakin, L. Schat, G. Kadereit, and A. M. Humphreys. 2023. Evolution of cold tolerance in the highly stress-tolerant samphires and relatives (Salicornieae: Amaranthaceae). Botanical Journal of the Linnean Society. https://doi.org/10.1093/botlinnean/boad009

Low temperature constitutes one of the main barriers to plant distributions, confining many clades to their ancestrally tropical biome. However, recent evidence suggests that transitions from tropical to temperate biomes may be more frequent than previously thought. Here, we study the evolution of cold and frost tolerance in the globally distributed and highly stress-tolerant Salicornieae (Salicornioideae, Amaranthaceae s.l.). We first generate a phylogenetic tree comprising almost all known species (85-90%), using newly generated (n = 106) and published nuclear-ribosomal and plastid sequences. Next, we use geographical occurrence data to document in which clades and geographical regions cold-tolerant species occur and reconstruct how cold tolerance evolved. Finally, we test for correlated evolution between frost tolerance and the annual life form. We find that frost tolerance has evolved independently in up to four Northern Hemisphere lineages but that annuals are no more likely to evolve frost tolerance than perennials, indicating the presence of different strategies for adapting to cold environments. Our findings add to mounting evidence for multiple independent out-of-the-tropics transitions among close relatives of flowering plants and raise new questions about the ecological and physiological mechanism(s) of adaptation to low temperatures in Salicornieae.

Kolanowska, M. 2023. Loss of fungal symbionts and changes in pollinator availability caused by climate change will affect the distribution and survival chances of myco-heterotrophic orchid species. Scientific Reports 13. https://doi.org/10.1038/s41598-023-33856-y

The first comprehensive species distribution models for orchid, its fungal symbionts and pollinator are presented. To evaluate impact of global warming on these organisms three different projections and four various climate change scenarios were analysed. The niche modelling was based on presence-only records of Limodorum abortivum , two species of Russula and three insects pollinating orchid ( Anthophora affinis, Bombus terrestris, Rhodanthidium septemdentatum ). Two sets of orchid predictions were examined—the first one included only climatic data and the second one was based on climate data and data on future distribution of orchid fungal symbionts. Overall, a poleward range shift is predicted to occur as a result of climate change and apparently global warming will be favorable for L. abortivum and its potential geographical range will expand. However, due to the negative effect of global warming on fungal symbionts of L. abortivum , the actual extension of the suitable niches of the orchid will be much limited. Considering future possibility of cross-pollination, the availability of A. affinis for L. abortivum will decrease and this bee will be available in the worst case scenarios only for 21% of orchid populations. On the other hand, the overlap of orchid and the buff-tailed bumblebee will increase and as much as 86.5% of plant populations will be located within B. terrestris potential range. Also the availability of R. septemdentatum will be higher than currently observed in almost all analysed climate change projections. This study showed the importance of inclusion of ecological factors in species distribution models as the climate data itself are not enough to estimate the future distribution of plant species. Moreover, the availability of pollen vectors which is crucial for long-term survival of orchid populations should be analysed in context of climate changes.

Zhang, W., H. Wang, T. Zhang, X. Fang, M. Liu, and H. Xiao. 2023. Geographic-genomic and geographic-phenotypic differentiation of the Aquilegia viridiflora complex. Horticulture Research. https://doi.org/10.1093/hr/uhad041

Abstract How species diverge into different lineages is a central issue in evolutionary biology. Despite the increasing evidence indicating that such divergences do not need geographic isolation, the correlation between the lineage divergence and the adaptive ecological divergence of phenotype corresponding to distributional is still unknown. In addition, gene flow has been widely detected during and through such diverging processes. We used one widely distributed Aquilegia viridiflora complex as a model system to examine genomic differentiation and corresponding phenotypic variations along geographic gradients. Our phenotypic analyses 20 populations from northwest to northeast China identified two phenotypic groups along the geographic cline. All examined traits are distinct between them although a few intermediate individuals occur in their contacting regions. We further sequenced the genomes of the representative individuals of each population. However, four distinct genetic lineages were detected based on nuclear genomes. In particular, we recovered numerous genetic hybrids in the contact regions of four lineages were recovered. Gene flow is widespread and continuous between four lineages but much higher between contacting lineages than geographically isolated lineages. Gene flow and natural selection might result in the inconsistency between heredity and phenotype. Moreover, many genes with fast lineage-specific mutations were identified to be involved in local adaptation. Our results suggest that both geographic isolation and local selection exerted by the environment and pollinators may together create geographic distributions of phenotypic variations as well as the underlying genomic divergences in numerous lineages.