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1.
BMC Genomics ; 25(1): 851, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39261781

RESUMEN

BACKGROUND: The WD40 domain, one of the most abundant in eukaryotic genomes, is widely involved in plant growth and development, secondary metabolic biosynthesis, and mediating responses to biotic and abiotic stresses. WD40 repeat (WD40) protein has been systematically studied in several model plants but has not been reported in the Capsicum annuum (pepper) genome. RESULTS: Herein, 269, 237, and 257 CaWD40 genes were identified in the Zunla, CM334, and Zhangshugang genomes, respectively. CaWD40 sequences from the Zunla genome were selected for subsequent analysis, including chromosomal localization, phylogenetic relationships, sequence characteristics, motif compositions, and expression profiling. CaWD40 proteins were unevenly distributed on 12 chromosomes, encompassing 19 tandem duplicate gene pairs. The 269 CaWD40s were divided into six main branches (A to F) with 17 different types of domain distribution. The CaWD40 gene family exhibited diverse expression patterns, and several genes were specifically expressed in flowers and seeds. Yeast two-hybrid (Y2H) and dual-luciferase assay indicated that CaWD40-91 could interact with CaAN1 and CaDYT1, suggesting its involvement in anthocyanin biosynthesis and male sterility in pepper. CONCLUSIONS: In summary, we systematically characterized the phylogeny, classification, structure, and expression of the CaWD40 gene family in pepper. Our findings provide a valuable foundation for further functional investigations on WD40 genes in pepper.


Asunto(s)
Antocianinas , Capsicum , Filogenia , Proteínas de Plantas , Capsicum/genética , Capsicum/metabolismo , Antocianinas/biosíntesis , Antocianinas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Regulación de la Expresión Génica de las Plantas , Infertilidad Vegetal/genética , Repeticiones WD40/genética , Familia de Multigenes , Perfilación de la Expresión Génica , Cromosomas de las Plantas/genética
2.
Plant Divers ; 46(4): 425-434, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39280975

RESUMEN

Orchidaceae are one of the largest families of angiosperms in terms of species richness. In the last decade, numerous studies have delved into reconstructing the phylogenetic framework of Orchidaceae, leveraging data from plastid, mitochondrial and nuclear sources. These studies have provided new insights into the systematics, diversification and biogeography of Orchidaceae, establishing a robust foundation for future research. Nevertheless, pronounced controversies persist regarding the precise placement of certain lineages within these phylogenetic frameworks. To address these discrepancies and deepen our understanding of the phylogenetic structure of Orchidaceae, we provide a comprehensive overview and analysis of phylogenetic studies focusing on contentious groups within Orchidaceae since 2015, delving into discussions on the underlying reasons for observed topological conflicts. We also provide a novel phylogenetic framework at the subtribal level. Furthermore, we examine the tempo and mode underlying orchid species diversity from the perspective of historical biogeography, highlighting factors contributing to extensive speciation. Ultimately, we delineate avenues for future research aimed at enhancing our understanding of Orchidaceae phylogeny and diversity.

3.
Molecules ; 29(17)2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39274905

RESUMEN

A novel and concise synthetic method for arenastatin A, a cytotoxic cyclic depsipeptide of marine origin, was developed in this study. The convergent assembly of the four segments, including the cross-metathesis reaction, gave a cyclization precursor, and Fmoc deprotection caused simultaneous macrocyclization. The Corey-Chaykovsky reaction using a chiral sulfur ylide afforded arenastatin A with complete stereoselectivity in the longest linear sequence of seven reaction steps from the known compound. Using this synthetic method, some analogs of segment B were prepared through a late-stage diversification strategy. The simple SN2 reaction of the thiolate toward the tosylate precursor, prepared using almost the same synthetic method as described above, provided the desired sulfide analogs.


Asunto(s)
Depsipéptidos , Estereoisomerismo , Depsipéptidos/síntesis química , Depsipéptidos/química , Estructura Molecular , Ciclización
4.
J Environ Manage ; 369: 122343, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39226805

RESUMEN

In the context of a global shift towards low-carbon energy systems, this paper provides an in-depth analysis of deep-sea mining's (DSM) potential role in enhancing global energy security. Addressing the growing demand for critical minerals essential for clean energy technologies, electric vehicles (EVs), and energy storage systems, the paper examines how DSM can diversify the global mineral supply and reduce reliance on geopolitically sensitive sources. It explores DSM's capacity to recalibrate energy prices, influence the competitive landscape of clean energy technologies, and shift geopolitical dynamics. The paper delves into the multi-faceted impacts of DSM on energy security, including geopolitical shifts, supply chain diversification, and environmental trade-offs. By providing a holistic view that links mineral supply security to sustainable energy transitions, this study extends beyond prior research focused mainly on the technical and environmental aspects of DSM. The findings illustrate DSM's intersection with international politics, its effect on energy pricing strategies, and the balance between resource exploitation and environmental stewardship. Strategic policy recommendations are offered to optimize DSM's benefits while minimizing its ecological impacts, aligning the emerging DSM industry with global sustainability goals. In addition to identifying challenges, the paper proposes actionable solutions, contributing a unique perspective to the discourse on DSM and energy security.


Asunto(s)
Minería , Conservación de los Recursos Naturales
5.
J Genet Couns ; 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39279161

RESUMEN

As of 2022, 89% of genetic counselors report being White, and 93% report being women. We examined diversity in genetic counseling (GC) program admission committees (ACs-who are responsible for deciding who will make up the future GC workforce) and student cohorts to understand the impact of recent diversification efforts, and where future work should be focused. One representative from each AC of the 57 accredited GC programs in North America in 2022 was invited to participate in a cross-sectional survey to provide information on the diversity of GC ACs and student cohorts between 2019 and 2022 for the following dimensions: race/ethnicity, gender, sexual orientation, disability status, neurodiversity, and rural or low socioeconomic status backgrounds. Members of 38/57 (67%) ACs participated. Using the Cochran-Armitage test for trends, significant increases were observed for the proportion of individuals of a racial/ethnic minority within ACs (from 9% in 2019 to 18% in 2022; p < 0.0001). There was no change for other minoritized social identities. There was no significant change over time in the proportion of students holding any of the minoritized social identities. A low correlation was found between the diversity of ACs and student cohorts. This study reaffirms the need for greater diversification efforts within ACs and student cohorts. Increased transparency about the social identities of AC members and about ACs' commitment to diversification may facilitate the diversification of the profession.

6.
bioRxiv ; 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39253459

RESUMEN

Antigenic variation, using large genomic repertoires of antigen-encoding genes, allows pathogens to evade host antibody. Many pathogens, including the African trypanosome Trypanosoma brucei, extend their antigenic repertoire through genomic diversification. While evidence suggests that T. brucei depends on the generation of new variant surface glycoprotein (VSG) genes to maintain a chronic infection, a lack of experimentally tractable tools for studying this process has obscured its underlying mechanisms. Here, we present a highly sensitive targeted sequencing approach for measuring VSG diversification. Using this method, we demonstrate that a Cas9-induced DNA double-strand break within the VSG coding sequence can induce VSG recombination with patterns identical to those observed during infection. These newly generated VSGs are antigenically distinct from parental clones and thus capable of facilitating immune evasion. Together, these results provide insight into the mechanisms of VSG diversification and an experimental framework for studying the evolution of antigen repertoires in pathogenic microbes.

7.
Data Brief ; 56: 110721, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39252778

RESUMEN

South Asia's Eastern Indo-Gangetic Plains (EIGP) is home to approximately 450 million people. This region is characterized by the highest global concentration of rural poverty and a predominant reliance on agriculture for nutritional sustenance and economic livelihoods. Agriculture in the EIGP is highly cereal-centric, making crop diversification indispensable for its development. This data article is part of the research conducted by an interdisciplinary team of researchers analysing the status and determinants of crop diversification in South Asia's EIGP. The data presented here were collected from 1,400 farm households across 72 communities in eight locations within the EIGP of India, Nepal, and Bangladesh during the year 2023. The research employed a simple random sampling method for empirical data collection. The primary agricultural decision-makers were given a tailored questionnaire comprising seven modules. These modules sought comprehensive data on livelihood practices, changes in agriculture, aspirations, diet, food security, mechanization, demographics, and asset ownership. The questionnaire was translated from English into Nepali and Bangla to facilitate a thorough understanding of the farmers' livelihoods in the study areas. The survey successfully ended with 1400 properly filled and captured questionnaires, which was quite representative. The cross-sectional data presented here describe location-specific farm-level crop distribution, enabling the analysis of geographic variations in crop diversification. The generation of this dataset addresses a significant gap in the availability of information on the current state of crop diversification in the EIGP, offering a foundational baseline for future research and interventions by regional governments and development partners. We employed the Herfindahl-Hirschman Index (HHI) to calculate crop diversification and a Tobit Regression Model to identify the region-specific determinants of crop diversification. The dataset is hereby made available as it is considered vital for regional policy and practical recommendations.

8.
Mol Phylogenet Evol ; 201: 108192, 2024 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-39255869

RESUMEN

Chitin-synthase (CHS) is found in most eukaryotes and has a complex evolutionary history. Research into CHS has mainly been in the context of biomineralization of mollusc shells an area of high interest due to the consequences of ocean acidification. Exploration of CHS at the genomic level in molluscs, the evolution of isoforms, their tissue distribution, and response to environmental challenges are largely unknown. Exploiting the extensive molecular resources for mollusc species it is revealed that bivalves possess the largest number of CHS genes (12-22) reported to date in eukaryotes. The evolutionary tree constructed at the class level of molluscs indicates four CHS Type II isoforms (A-D) probably existed in the most recent common ancestor, and Type II-A (Type II-A-1/Type II-A-2) and Type II-C (Type II-C-1/Type II-C-2) underwent further differentiation. Non-specific loss of CHS isoforms occurred at the class level, and in some Type II (B-D groups) isoforms the myosin head domain, which is associated with shell formation, was not preserved and highly species-specific tissue expression of CHS isoforms occurred. These observations strongly support the idea of CHS functional diversification with shell biomineralization being one of several important functions. Analysis of transcriptome data uncovered the species-specific potential of CHS isoforms in shell formation and a species-specific response to ocean acidification (OA). The impact of OA was not CHS isoform-dependent although in Mytilus, Type I-B and Type II-D gene expression was down-regulated in both M. galloprovincialis and M. coruscus. In summary, during CHS evolution the gene family expanded in bivalves generating a large diversity of isoforms with different structures and with a ubiquitous tissue distribution suggesting that chitin is involved in many biological functions. These findings provide insight into CHS evolution in molluscs and lay the foundation for research into their function and response to environmental changes.

9.
Heliyon ; 10(16): e35844, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39224253

RESUMEN

Cocoa farmers in Nigeria adopt crop diversification to safeguard the food security of their households. Although credit and land are thought to play a vital role in crop diversification, they continue to have limited access to credit and land. This study investigated the linkages between access to credit, land use, crop diversification, and food security with a focus on cocoa farming households. A multistage sampling procedure was used to obtain data for the study. Data were analyzed with the aid of descriptive statistics, the Heifindahl index, the Tobit regression model, the food consumption score, and the ordered Logit regression model. The results for the entire respondents showed mean values of 55 years for age, 31 years for farming experience, 6 people for household size, and 5 ha for farm size. Heifindahl index shows 38.67 % of the respondents had low crop diversification in the study area. Tobit regression model reveals that access to credit, farming experience, cooperative organization, access to extension service, farm size, distance to farms, and labour are the main albeit significant factors that determine crop diversification among cocoa farming households. Food consumption score revealed that 46.67 % were poor, 30.67 % were at the borderline and about 27.67 % were within the acceptable threshold. The ordered logit model revealed that crop diversification index, formal education, access to credit, farm size, land use, and farming experience have a significant influence on the food security of households. The study concluded that there is a positive relationship between access to credit, land use, crop diversification, and food security. Therefore, the government and financial institutions should make credit facilities accessible to cocoa farmers to improve their livelihood.

10.
Evolution ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39240141

RESUMEN

Our understanding of the evolution of social mating systems is largely based on an atemporal ecological framework, whereas macroevolutionary and phylogenetic perspectives looking at the causes of mating systems variation are less developed. Here, we present analyses of the evolution of social mating systems in birds at an unprecedented scale, including 66% of the world's birds and using trait-dependent speciation and extinction models. We found that lekking (no social bond between the sexes) is very rarely lost, in accordance with the hypothesis that a male shifting to investing in one rather than multiple mates would suffer a severe fitness cost. In contrast, resource-defense polygamous lineages (with a weak, transient socio-sexual bond) frequently revert back to monogamy (strong, durable socio-sexual bond) and have an elevated extinction fraction. We tentatively attribute this to the impossibility for females to settle on an optimal parental care strategy under this system. Finally, we found that most gains of lekking have been directly from monogamy, rather than through an intermediate stage of resource-defense polygamy.

11.
Ann Bot ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39221840

RESUMEN

BACKGROUND AND AIMS: Previous phylogenetic studies on the pharmaceutically significant genus Paris (Melanthiaceae) have consistently revealed substantial cytonuclear discordance, yet the underlying mechanism responsible for this phenomenon remains elusive. This study aims to reconstruct a robust nuclear backbone phylogeny and elucidate the potential evolutionarily complex events contributing to previously observed cytonuclear discordance within Paris. METHODS: Based on a comprehensive set of nuclear low-copy orthologous genes obtained from transcriptomic data, the intrageneric phylogeny of Paris, along with its phylogenetic relationships to allied genera were inferred, using coalescent and concatenated approaches. The analysis of gene tree discordance and reticulate evolution, in conjunction with an incomplete lineage sorting (ILS) simulation, was conducted to explore potential hybridization and ILS events in the evolutionary history of Paris and assess their contribution to the discordance of gene trees. KEY RESULTS: The nuclear phylogeny unequivocally confirmed the monophyly of Paris and its sister relationship with Trillium, while widespread incongruences in gene trees were observed at the majority of internal nodes within Paris. The reticulate evolution analysis identified five instances of hybridization events in Paris, indicating that hybridization events might have recurrently occurred throughout the evolutionary history of Paris. In contrast, the ILS simulations revealed that only two internal nodes within sect. Euthyra experienced ILS events. CONCLUSIONS: Our data suggest that the previously observed cytonuclear discordance in the phylogeny of Paris can primarily be attributed to recurrent hybridization events, with secondary contributions from infrequent ILS events. The recurrent hybridization events in the evolutionary history of Paris not only drove lineage diversification and speciation but also facilitated morphological innovation, and enhanced ecological adaptability. Therefore, artificial hybridization has great potential for breeding medicinal Paris species. These findings significantly contribute to our comprehensive understanding of the evolutionary complexity of this pharmaceutically significant plant lineage, thereby facilitating effective exploration and conservation efforts.

12.
Artículo en Inglés | MEDLINE | ID: mdl-39113287

RESUMEN

INTRODUCTION: Exposure to bias in clinical learning environments may undermine students' confidence, cause emotional harm, impede learning, and potentially delay graduation. However, little is known about the prevalence of bias experienced by midwifery students in the United States. This cross-sectional, descriptive study aimed to quantify clinical midwifery students' experiences of bias based on 7 self-identified characteristics (gender identity, race or ethnicity, body size, age, sexual orientation, religion, and occupational background). Additionally, this research explored the impact of bias on student well-being, learning, and professional commitment. METHODS: The survey consisted of 39 items addressing (1) prevalence and types of bias, (2) emotional impact and influence on clinical learning, (3) ways students coped, (4) whether anyone spoke up at the time bias occurred, (5) whether students reported bias to faculty, and (6) impact of bias on commitment to midwifery. The survey was distributed to midwifery students and recent graduates in 2022 via American College of Nurse-Midwives email discussion lists and social media. Participants were eligible if they were in a clinical rotation in an Accreditation Commission for Midwifery Education-accredited midwifery program between 2019 and 2022. RESULTS: Surveys were returned by 383 participants, with 301 meeting inclusion criteria. Most participants (66.5%) reported personally experiencing or witnessing bias against at least 1 of 7 personal characteristics. The most commonly reported biases were related to gender, occupational background, age, and race or ethnicity. Only half of the participants reported these occurrences to someone with academic authority, and nearly a third considered withdrawing from their educational programs. DISCUSSION: In this study bias was common and significantly impacted students. These results underscore the need for creative and bold interventions at personal, educational, and institutional levels to prevent and mitigate bias. Safeguarding clinical learning environments will enable students to thrive, graduate with confidence and competence, and thereby contribute to the diversification and strengthening of the midwifery profession.

13.
Diabet Med ; : e15422, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39118237

RESUMEN

AIMS: Very low-calorie diet (VLCD) can induce weight loss and diabetes remission (DR) amongst people with obesity and recent-onset type 2 diabetes (T2D). We aimed to determine the effectiveness and acceptability of VLCD in achieving DR amongst Sri Lankan adults with T2D. METHODS: A retrospective analysis was conducted in a diabetes practice where VLCD-based Diabetes Remission Programme (VDRP) was offered for adults (>18 years) with T2D for <3 years and body mass index over 25 kg/m2. VLCD (~800 kcal/day, provided with/without diet replacement formula) was offered for 8-12 weeks, followed by gradual food reintroduction and exercise. DR was defined as HbA1c <6.5% at least 3 months after stopping glucose-lowering medications. RESULTS: A total of 170 participants who enrolled in the VDRP (mean age 38.4 years [±11.1], men 68%, mean baseline HbA1c 86.9 [±18.1] mmol/mol (10.1 [±2.1]%), median duration of T2D 2 years [IQR 1-2]) and 87 (51%) of them followed the programme (attended at least one follow-up visit). Amongst the individuals who followed the VDRP, 40.2% achieved DR (35/87), compared with 2.4% (2/83) amongst those who did not follow the VDRP (aHR 9.3, 95% CI 2.2-16.4, p = 0.002). The proportion achieving normoglycaemia (HbA1c < 6.5%) but continued to take glucose-lowering medication was 20/87 among VDRP followers and 20/85 amongst VDRP non-followers. The commonest reasons for not following the VDRP were too restrictive dietary quantity (92%) and difficulties in finding recommended food items (67%). Majority (79%) would recommend VDRP to others. CONCLUSIONS: VDRP is effective in achieving T2D remission amongst Sri Lankan adults with recently diagnosed T2D and obesity. Over half of the participants followed the programme and over 75% would recommend it to others, indicating good acceptability.

14.
MethodsX ; 13: 102855, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39105087

RESUMEN

Study of morphogenesis and its regulation requires analytical tools that enable simultaneous assessment of processes operating at cellular level, such as synthesis of transcription factors (TF), with their effects at the tissue scale. Most current studies conduct histological, cellular and immunochemical (IHC) analyses in separate steps, introducing inevitable biases in finding and alignment of areas of interest at vastly distinct scales of organization, as well as image distortion associated with image repositioning or file modifications. These problems are particularly severe for longitudinal analyses of growing structures that change size and shape. Here we introduce a python-based application for automated and complete whole-slide measurement of expression of multiple TFs and associated cellular morphology. The plugin collects data at customizable scale from the cell-level to the entire structure, records each data point with positional information, accounts for ontogenetic transformation of structures and variation in slide positioning with scalable grid, and includes a customizable file manager that outputs collected data in association with full details of image classification (e.g., ontogenetic stage, population, IHC assay). We demonstrate the utility and accuracy of this application by automated measurement of morphology and associated expression of eight TFs for more than six million cells recorded with full positional information in beak tissues across 12 developmental stages and 25 study populations of a wild passerine bird. Our script is freely available as an open-source Fiji plugin and can be applied to IHC slides from any imaging platforms and transcriptional factors.

15.
J Exp Bot ; 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39171373

RESUMEN

The distribution of chlorophylls in eggplant (Solanum melongena) peel exhibits either a uniform pattern or an irregular green netting. The latter, manifested as a gradient of dark green netting intensified in the proximal part of the fruit on a pale green background, is common in wild relatives and some eggplant landraces. Despite the selection of uniform chlorophylls during domestication, the netting pattern contributes to a greater diversity of fruit colours. Here, we have used over 2,300 individuals from different populations, including a multi-parental MAGIC population for candidate genomic region identification, an F2 population for BSA-Seq, and advanced backcrosses for edges-to-core fine-mapping, to identify SmGLK2 gene as responsible for the irregular netting in eggplant fruits. We have also analysed the gene sequence of 178 S. melongena accessions and 22 wild relative species for tracing the evolutionary changes that the gene has undergone during domestication. Three different mutations were identified leading to the absence of netting. The main causative indel induces a premature stop codon disrupting the protein conformation and function, which was confirmed by western blotting analysis and confocal microscopy observations. SmGLK2 has a major role in regulating chlorophyll biosynthesis in eggplant fruit peel.

16.
Sci China Life Sci ; 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39190128

RESUMEN

Understanding the maintenance and shift in reproductive strategies is a fundamental question in evolutionary research. Although many efforts have been made to compare different reproductive strategies, the association between reproductive strategies and lineage divergence is largely unknown. To explore the impact of different reproductive strategies on lineage divergence, we investigated the evolution of clonality in Saxifraga sect. Irregulares+Heterisia. By integrating several lines of evidence, we found that the loss of clonality in Irregulares+Heterisia was associated with a progressive increase in diversification rate and intraspecific morphological diversity but with a reduction in species distribution range. Our findings provide insights into the ecological and evolutionary effects of different reproductive strategies, suggesting the necessity of integrating clonality into ecological and evolutional research.

17.
J Environ Manage ; 367: 122011, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39094415

RESUMEN

Photosynthetic carbon sequestration and microbial carbon metabolism are major processes of algae-bacteria interactions, affecting pollutant degradation as well as fundamental biogeochemical cycles in aquatic systems. Human-induced land-use changes greatly alter the molecular composition and input of terrestrial dissolved organic matter (DOM) in inland lakes. However, how the origin of DOM leads to varying effects on phycosphere microbial communities or molecular composition of DOM, e.g., via carbon metabolism, has been little studied in freshwater. Here, we incubated the cyanobacterium Microcystis aeruginosa and a bacterial community from natural lakes to establish an alga-bacteria model system. This allowed us to investigate how DOM from different sources affects phycosphere microbial diversity and DOM diversification. We showed that Suwannee River fulvic acid (SRFA), Suwannee River natural organic matter (SRNOM) and cropland lake DOM promote algal growth, whereas DOM from an urban lake inhibits algal growth. Algal metabolites and DOM together shaped the chemotaxis response of phycosphere communities. High-resolution mass spectrometry analysis demonstrated that DOM chemo-diversity tended to become uniform after interactions of diverse DOM sources with the algae-bacteria symbiosis system. Molecular thermodynamic analysis of DOM based on a substrate-explicit model further verified that microbial interactions render DOM less bioavailable and thus increase recalcitrant DOM formation. Metabolome analysis uncovered that DOM addition intensifies metabolic pathways related to labile and recalcitrant DOM utilization (mainly lignin/carboxyl-rich alicyclic molecule (CRAM)-like DOM, unsaturated hydrocarbon), whereby cofactor and vitamin metabolism represented an extremely strong activity in all metabolic pathways. Our results highlight covariation and interactions of DOM with microbial metabolism at the molecular level and expands our understanding of microbially mediated DOM shaping aquatic carbon cycling.


Asunto(s)
Carbono , Lagos , Lagos/microbiología , Carbono/metabolismo , Humanos , Benzopiranos , Bacterias/metabolismo
18.
J Integr Plant Biol ; 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39152659

RESUMEN

Coniferous forests are under severe threat of the rapid anthropogenic climate warming. Abies (firs), the fourth-largest conifer genus, is a keystone component of the boreal and temperate dark-coniferous forests and harbors a remarkably large number of relict taxa. However, the uncertainty of the phylogenetic and biogeographic history of Abies significantly impedes our prediction of future dynamics and efficient conservation of firs. In this study, using 1,533 nuclear genes generated from transcriptome sequencing and a complete sampling of all widely recognized species, we have successfully reconstructed a robust phylogeny of global firs, in which four clades are strongly supported and all intersectional relationships are resolved, although phylogenetic discordance caused mainly by incomplete lineage sorting and hybridization was detected. Molecular dating and ancestral area reconstruction suggest a Northern Hemisphere high-latitude origin of Abies during the Late Cretaceous, but all extant firs diversified during the Miocene to the Pleistocene, and multiple continental and intercontinental dispersals took place in response to the late Neogene climate cooling and orogenic movements. Notably, four critically endangered firs endemic to subtropical mountains of China, including A. beshanzuensis, A. ziyuanensis, A. fanjingshanensis and A. yuanbaoshanensis from east to west, have different origins and evolutionary histories. Moreover, three hotspots of species richness, including western North America, central Japan, and the Hengduan Mountains, were identified in Abies. Elevation and precipitation, particularly precipitation of the coldest quarter, are the most significant environmental factors driving the global distribution pattern of fir species diversity. Some morphological traits are evolutionarily constrained, and those linked to elevational variation (e.g., purple cone) and cold resistance (e.g., pubescent branch and resinous bud) may have contributed to the diversification of global firs. Our study sheds new light on the spatiotemporal evolution of global firs, which will be of great help to forest management and species conservation in a warming world.

19.
Mol Ecol ; : e17498, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39152668

RESUMEN

Over the last 6 million years, the arid Australian Eremaean Zone (EZ) has remained as dry as it is today. A widely accepted hypothesis suggests that the flora and fauna of arid regions were more broadly distributed before aridification began. In Australia, this process started around 20 million years ago (Ma), leading to gradual speciation as the climate became increasingly arid. Here, we use genomic data to investigate the biogeography and timing of divergence of native allotetraploid tobaccos, Nicotiana section Suaveolentes (Solanaceae). The original allotetraploid migrants from South America were adapted to mesic areas of Australia and recently radiated in the EZ, including in sandy dune fields (only 1.2 Ma old), after developing drought adaptations. Coalescent and maximum likelihood analyses suggest that Nicotiana section Suaveolentes arrived on the continent around 6 Ma, with the ancestors of the Pilbara (Western Australian) lineages radiating there at the onset of extreme aridity 5 Ma by locally adapting to these various ancient, highly stable habitats. The Pilbara thus served as both a mesic refugium and cradle for adaptations to harsher conditions, due to its high topographical diversity, providing microhabitats with varying moisture levels and its proximity to the ocean, which buffers against extreme aridity. This enabled species like Nicotiana to survive in mesic refugia and subsequently adapt to more arid conditions. These results demonstrate that initially poorly adapted plant groups can develop novel adaptations in situ, permitting extensive and rapid dispersal despite the highly variable and unpredictable extreme conditions of the EZ.

20.
New Phytol ; 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39166427

RESUMEN

Horizontal gene transfer (HGT) is a major driving force in the evolution of prokaryotic and eukaryotic genomes. Despite recent advances in distribution and ecological importance, the extensive pattern, especially in seed plants, and post-transfer adaptation of HGT-acquired genes in land plants remain elusive. We systematically identified 1150 foreign genes in 522 land plant genomes that were likely acquired via at least 322 distinct transfers from nonplant donors and confirmed that recent HGT events were unevenly distributed between seedless and seed plants. HGT-acquired genes evolved to be more similar to native genes in terms of average intron length due to intron gains, and HGT-acquired genes containing introns exhibited higher expression levels than those lacking introns, suggesting that intron gains may be involved in the post-transfer adaptation of HGT in land plants. Functional validation of bacteria-derived gene GuaD in mosses and gymnosperms revealed that the invasion of foreign genes introduced a novel bypass of guanine degradation and resulted in the loss of native pathway genes in some gymnosperms, eventually shaping three major types of guanine metabolism in land plants. We conclude that HGT has played a critical role in land plant evolution.

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