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Carvalho-Madrigal S, Sanín MJ. The role of introgressive hybridization in shaping the geographically isolated gene pools of wax palm populations (genus Ceroxylon). Mol Phylogenet Evol 2024; 193:108013. [PMID: 38195012 DOI: 10.1016/j.ympev.2024.108013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/22/2023] [Accepted: 01/06/2024] [Indexed: 01/11/2024]
Abstract
The speciation continuum is the process by which genetic groups diverge until they reach reproductive isolation. It has become common in the literature to show that this process is gradual and flickering, with possibly many instances of secondary contact and introgression after divergence has started. The level of divergence might vary among genomic regions due to, among others, the different forces and roles of selection played by the shared regions. Through hybrid capture, we sequenced ca. 4,000 nuclear regions in populations of six species of wax palms, five of which form a monophyletic group (genus Ceroxylon, Arecaceae: Ceroxyloideae). We show that in this group, the different populations show varying degrees of introgressive hybridization, and two of them are backcrosses of the other three 'pure' species. This is particularly interesting because these three species are dioecious, have a shared main pollinator, and have slightly overlapping reproductive seasons but highly divergent morphologies. Our work supports shows wax palms diverge under positive and background selection in allopatry, and hybridize due to secondary contact and inefficient reproductive barriers, which sustain genetic diversity. Introgressed regions are generally not under positive selection. Peripheral populations are backcrosses of other species; thus, introgressive hybridization is likely modulated by demographic effects rather than selective pressures. In general, these species might function as an 'evolutionary syngameon' where expanding, peripheral, small, and isolated populations maintain diversity by crossing with available individuals of other wax palms. In the Andean context, species can benefit from gained variation from a second taxon or the enhancement of population sizes by recreating a common genetic pool.
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Affiliation(s)
| | - María José Sanín
- School of Mathematical and Natural Sciences, Arizona State University, West Valley Campus, Glendale, United States.
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Zhao W, Gao J, Hall D, Andersson BA, Bruxaux J, Tomlinson KW, Drouzas AD, Suyama Y, Wang XR. Evolutionary radiation of the Eurasian Pinus species under pervasive gene flow. THE NEW PHYTOLOGIST 2024. [PMID: 38515228 DOI: 10.1111/nph.19694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 03/04/2024] [Indexed: 03/23/2024]
Abstract
Evolutionary radiation, a pivotal aspect of macroevolution, offers valuable insights into evolutionary processes. The genus Pinus is the largest genus in conifers withc . $$ c. $$ 90% of the extant species emerged in the Miocene, which signifies a case of rapid diversification. Despite this remarkable history, our understanding of the mechanisms driving radiation within this expansive genus has remained limited. Using exome capture sequencing and a fossil-calibrated phylogeny, we investigated the divergence history, niche diversification, and introgression among 13 closely related Eurasian species spanning climate zones from the tropics to the boreal Arctic. We detected complex introgression among lineages in subsection Pinus at all stages of the phylogeny. Despite this widespread gene exchange, each species maintained its genetic identity and showed clear niche differentiation. Demographic analysis unveiled distinct population histories among these species, which further influenced the nucleotide diversity and efficacy of purifying and positive selection in each species. Our findings suggest that radiation in the Eurasian pines was likely fueled by interspecific recombination and further reinforced by their adaptation to distinct environments. Our study highlights the constraints and opportunities for evolutionary change, and the expectations of future adaptation in response to environmental changes in different lineages.
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Affiliation(s)
- Wei Zhao
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, SE-90187, Sweden
| | - Jie Gao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China
| | - David Hall
- Forestry Research Institute of Sweden (Skogforsk), Sävar, SE-91833, Sweden
| | - Bea Angelica Andersson
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, SE-90187, Sweden
| | - Jade Bruxaux
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, SE-90187, Sweden
| | - Kyle W Tomlinson
- Center for Integrative Conservation & Yunnan Key Laboratory for Conservation of Tropical Rainforests and Asian Elephant, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, 666303, China
| | - Andreas D Drouzas
- Laboratory of Systematic Botany and Phytogeography, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece
| | - Yoshihisa Suyama
- Graduate School of Agricultural Science, Tohoku University, Miyagi, 989-6711, Japan
| | - Xiao-Ru Wang
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, SE-90187, Sweden
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
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Iqbal MA, Hadlich F, Reyer H, Oster M, Trakooljul N, Murani E, Perdomo‐Sabogal A, Wimmers K, Ponsuksili S. RNA-Seq-based discovery of genetic variants and allele-specific expression of two layer lines and broiler chicken. Evol Appl 2023; 16:1135-1153. [PMID: 37360029 PMCID: PMC10286233 DOI: 10.1111/eva.13557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 06/28/2023] Open
Abstract
Recent advances in the selective breeding of broilers and layers have made poultry production one of the fastest-growing industries. In this study, a transcriptome variant calling approach from RNA-seq data was used to determine population diversity between broilers and layers. In total, 200 individuals were analyzed from three different chicken populations (Lohmann Brown (LB), n = 90), Lohmann Selected Leghorn (LSL, n = 89), and Broiler (BR, n = 21). The raw RNA-sequencing reads were pre-processed, quality control checked, mapped to the reference genome, and made compatible with Genome Analysis ToolKit for variant detection. Subsequently, pairwise fixation index (F ST) analysis was performed between broilers and layers. Numerous candidate genes were identified, that were associated with growth, development, metabolism, immunity, and other economically significant traits. Finally, allele-specific expression (ASE) analysis was performed in the gut mucosa of LB and LSL strains at 10, 16, 24, 30, and 60 weeks of age. At different ages, the two-layer strains showed significantly different allele-specific expressions in the gut mucosa, and changes in allelic imbalance were observed across the entire lifespan. Most ASE genes are involved in energy metabolism, including sirtuin signaling pathways, oxidative phosphorylation, and mitochondrial dysfunction. A high number of ASE genes were found during the peak of laying, which were particularly enriched in cholesterol biosynthesis. These findings indicate that genetic architecture as well as biological processes driving particular demands relate to metabolic and nutritional requirements during the laying period shape allelic heterogeneity. These processes are considerably affected by breeding and management, whereby elucidating allele-specific gene regulation is an essential step towards deciphering the genotype to phenotype map or functional diversity between the chicken populations. Additionally, we observed that several genes showing significant allelic imbalance also colocalized with the top 1% of genes identified by the FST approach, suggesting a fixation of genes in cis-regulatory elements.
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Affiliation(s)
| | - Frieder Hadlich
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
| | - Henry Reyer
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
| | - Michael Oster
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
| | - Nares Trakooljul
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
| | - Eduard Murani
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
| | | | - Klaus Wimmers
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
- Faculty of Agricultural and Environmental SciencesUniversity RostockRostockGermany
| | - Siriluck Ponsuksili
- Research Institute for Farm Animal BiologyInstitute of Genome BiologyDummerstorfGermany
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Feng S, Wan W, Li Y, Wang D, Ren G, Ma T, Ru D. Transcriptome-based analyses of adaptive divergence between two closely related spruce species on the Qinghai-Tibet plateau and adjacent regions. Mol Ecol 2023; 32:476-491. [PMID: 36320185 DOI: 10.1111/mec.16758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 10/07/2022] [Accepted: 10/17/2022] [Indexed: 11/17/2022]
Abstract
Speciation among populations connected by gene flow is driven by adaptation to different environments, but underlying gene-environment associations remain largely unknown. Here, 162 individuals from 32 populations were sampled to obtain 191,648 independent single nucleotide polymorphisms (SNPs) across the genomes of two closely related spruce species, Picea asperata and Picea crassifolia, which occur on the Qinghai-Tibet Plateau and in surrounding regions. Using the SNP data set, genotype-environment associations and demographic modelling were used to examine local adaptation and genetic divergence between these two species. While morphologically similar, the two Picea species were genetically differentiated in multiple analyses. These species diverged despite continuous gene flow, and their initial divergence was dated back to the late Quaternary. The effective population sizes of both species have expanded since their divergence, as confirmed by niche distribution simulations. A total of 6365 genes were associated with the tested environmental variables; of these, 41 were positively selected in P. asperata and were mainly associated with temperature, while 83 were positively selected in P. crassifolia and were primarily associated with precipitation. These results deepen our understanding of the adaptive divergence and demographic histories of these two spruce species and highlight the importance of genomic data in deciphering the environmental selection underlying Quaternary interspecific divergence.
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Affiliation(s)
- Shuo Feng
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - Wei Wan
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - Yang Li
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - DongLei Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Guangpeng Ren
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Tao Ma
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Dafu Ru
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
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Fang T, Zhou S, Qian C, Yan X, Yin X, Fan X, Zhao P, Liao Y, Shi L, Chang Y, Ma XF. Integrated metabolomics and transcriptomics insights on flavonoid biosynthesis of a medicinal functional forage, Agriophyllum squarrosum (L.), based on a common garden trial covering six ecotypes. FRONTIERS IN PLANT SCIENCE 2022; 13:985572. [PMID: 36204072 PMCID: PMC9530573 DOI: 10.3389/fpls.2022.985572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
Agriophyllum squarrosum (L.) Moq., well known as sandrice, is an important wild forage in sandy areas and a promising edible and medicinal resource plant with great domestication potential. Previous studies showed flavonoids are one of the most abundant medicinal ingredients in sandrice, whereby isorhamnetin and isorhamnetin-3-glycoside were the top two flavonols with multiple health benefits. However, the molecular regulatory mechanisms of flavonoids in sandrice remain largely unclear. Based on a common garden trial, in this study, an integrated transcriptomic and flavonoids-targeted metabolomic analysis was performed on the vegetative and reproductive periods of six sandrice ecotypes, whose original habitats covered a variety of environmental factor gradients. Multiple linear stepwise regression analysis unveiled that flavonoid accumulation in sandrice was positively correlated with temperature and UVB and negatively affected by precipitation and sunshine duration, respectively. Weighted co-expression network analysis (WGCNA) indicated the bHLH and MYB transcription factor (TF) families might play key roles in sandrice flavonoid biosynthesis regulation. A total of 22,778 differentially expressed genes (DEGs) were identified between ecotype DL and ecotype AEX, the two extremes in most environmental factors, whereby 85 DEGs could be related to known flavonoid biosynthesis pathway. A sandrice flavonoid biosynthesis network embracing the detected 23 flavonoids in this research was constructed. Gene families Plant flavonoid O-methyltransferase (AsPFOMT) and UDP-glucuronosyltransferase (AsUGT78D2) were identified and characterized on the transcriptional level and believed to be synthases of isorhamnetin and isorhamnetin-3-glycoside in sandrice, respectively. A trade-off between biosynthesis of rutin and isorhamnetin was found in the DL ecotype, which might be due to the metabolic flux redirection when facing environmental changes. This research provides valuable information for understanding flavonoid biosynthesis in sandrice at the molecular level and laid the foundation for precise development and utilization of this functional resource forage.
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Affiliation(s)
- Tingzhou Fang
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Shanshan Zhou
- Faculty of Environmental Science and Engineering, Shanxi Institute of Science and Technology, Jincheng, China
| | - Chaoju Qian
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xia Yan
- Key Laboratory of Eco-Hydrology of Inland River Basin, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- Marsgreen Biotech Jiangsu Co., Ltd., Haian, China
| | - Xiaoyue Yin
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xingke Fan
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Pengshu Zhao
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Yuqiu Liao
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Liang Shi
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Yuxiao Chang
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Xiao-Fei Ma
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Department of Ecology and Agriculture Research, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- Marsgreen Biotech Jiangsu Co., Ltd., Haian, China
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Suraby EJ, Sruthi KB, Antony G. Genome-wide identification of type III effectors and other virulence factors in Ralstonia pseudosolanacearum causing bacterial wilt in ginger (Zingiber officinale). Mol Genet Genomics 2022; 297:1371-1388. [PMID: 35879566 DOI: 10.1007/s00438-022-01925-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/04/2022] [Indexed: 10/16/2022]
Abstract
Ralstonia pseudosolanacearum causes bacterial wilt in ginger, reducing ginger production worldwide. We sequenced the whole genome of a highly virulent phylotype I, race 4, biovar 3 Ralstonia pseudosolanacearum strain GRsMep isolated from a severely infected ginger field in India. R. pseudosolanacearum GRsMep genome is organised into two replicons: chromosome and megaplasmid with a total genome size of 5,810,605 bp. This strain encodes approximately 72 effectors which include a combination of core effectors as well as highly variable, diverse repertoire of type III effectors. Comparative genome analysis with GMI1000 identified conservation in the genes involved in the general virulence mechanism. Our analysis identified type III effectors, RipBJ and RipBO as present in GRsMep but absent in the reported genomes of other strains infecting Zingiberaceae family. GRsMep contains 126 unique genes when compared to the pangenome of the Ralstonia strains that infect the Zingiberaceae family. The whole-genome data of R. pseudosolanacearum strain will serve as a resource for exploring the evolutionary processes that structure and regulate the virulence determinants of the strain. Pathogenicity testing of the transposon insertional mutant library of GRsMep through virulence assay on ginger plants identified a few candidate virulence determinants specific to bacterial wilt in ginger.
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Affiliation(s)
- Erinjery Jose Suraby
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - K Bharathan Sruthi
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India
| | - Ginny Antony
- Department of Plant Science, Central University of Kerala, Periye, 671320, Kasaragod, Kerala, India.
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Yu C, Huang J, Wu Q, Zhang C, Li XL, Xu X, Feng S, Zhan X, Chen Z, Wang H, Shen C. Role of female-predominant MYB39-bHLH13 complex in sexually dimorphic accumulation of taxol in Taxus media. HORTICULTURE RESEARCH 2022; 9:uhac062. [PMID: 35769613 PMCID: PMC9233167 DOI: 10.1093/hr/uhac062] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 02/28/2022] [Indexed: 05/19/2023]
Abstract
Taxus trees are major natural sources for the extraction of taxol, an anti-cancer agent used worldwide. Taxus media is a dioecious woody tree with high taxol yield. However, the sexually dimorphic accumulation of taxoids in T. media is largely unknown. Our study revealed high accumulation of taxoids in female T. media trees using a UPLC-MS/MS method. Thereafter, many differential metabolites and genes between female and male T. media trees were identified using metabolomic and transcriptomic analyses, respectively. Most of the taxol-related genes were predominantly expressed in female trees. A female-specific R2R3-MYB transcription factor gene, TmMYB39, was identified. Furthermore, bimolecular fluorescence complementation and yeast two-hybrid assays suggested the potential interaction between TmMYB39 and TmbHLH13. Several taxol biosynthesis-related promoter sequences were isolated and used for the screening of MYB recognition elements. The electrophoretic mobility shift assay indicated that TmMYB39 could bind to the promoters of the GGPPS, T10OH, T13OH, and TBT genes. Interaction between TmMYB39 and TmbHLH13 transactivated the expression of the GGPPS and T10OH genes. TmMYB39 might function in the transcriptional regulation of taxol biosynthesis through an MYB-bHLH module. Our results give a potential explanation for the sexually dimorphic biosynthesis of taxol in T. media.
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Affiliation(s)
- Chunna Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Jiefang Huang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Qicong Wu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Chengchao Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Xiao-lin Li
- State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Xinyun Xu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Shangguo Feng
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Xiaori Zhan
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Zhehao Chen
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
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Liu L, Wang Z, Su Y, Wang T. Population transcriptomic sequencing reveals allopatric divergence and local adaptation in Pseudotaxus chienii (Taxaceae). BMC Genomics 2021; 22:388. [PMID: 34039278 PMCID: PMC8157689 DOI: 10.1186/s12864-021-07682-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 05/05/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Elucidating the effects of geography and selection on genetic variation is critical for understanding the relative importance of adaptation in driving differentiation and identifying the environmental factors underlying its occurrence. Adaptive genetic variation is common in tree species, especially widely distributed long-lived species. Pseudotaxus chienii can occupy diverse habitats with environmental heterogeneity and thus provides an ideal material for investigating the process of population adaptive evolution. Here, we characterize genetic and expression variation patterns and investigate adaptive genetic variation in P. chienii populations. RESULTS We generated population transcriptome data and identified 13,545 single nucleotide polymorphisms (SNPs) in 5037 unigenes across 108 individuals from 10 populations. We observed lower nucleotide diversity (π = 0.000701) among the 10 populations than observed in other gymnosperms. Significant negative correlations between expression diversity and nucleotide diversity in eight populations suggest that when the species adapts to the surrounding environment, gene expression and nucleotide diversity have a reciprocal relationship. Genetic structure analyses indicated that each distribution region contains a distinct genetic group, with high genetic differentiation among them due to geographical isolation and local adaptation. We used FST outlier, redundancy analysis, and latent factor mixed model methods to detect molecular signatures of local adaptation. We identified 244 associations between 164 outlier SNPs and 17 environmental variables. The mean temperature of the coldest quarter, soil Fe and Cu contents, precipitation of the driest month, and altitude were identified as the most important determinants of adaptive genetic variation. Most candidate unigenes with outlier signatures were related to abiotic and biotic stress responses, and the monoterpenoid biosynthesis and ubiquitin-mediated proteolysis KEGG pathways were significantly enriched in certain populations and deserve further attention in other long-lived trees. CONCLUSIONS Despite the strong population structure in P. chienii, genomic data revealed signatures of divergent selection associated with environmental variables. Our research provides SNPs, candidate unigenes, and biological pathways related to environmental variables to facilitate elucidation of the genetic variation in P. chienii in relation to environmental adaptation. Our study provides a promising tool for population genomic analyses and insights into the molecular basis of local adaptation.
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Affiliation(s)
- Li Liu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhen Wang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yingjuan Su
- School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China.
- Research Institute of Sun Yat-sen University in Shenzhen, Shenzhen, Guangdong, China.
| | - Ting Wang
- College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China.
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De La Torre AR, Wilhite B, Puiu D, St. Clair JB, Crepeau MW, Salzberg SL, Langley CH, Allen B, Neale DB. Dissecting the Polygenic Basis of Cold Adaptation Using Genome-Wide Association of Traits and Environmental Data in Douglas-fir. Genes (Basel) 2021; 12:110. [PMID: 33477542 PMCID: PMC7831106 DOI: 10.3390/genes12010110] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 02/06/2023] Open
Abstract
Understanding the genomic and environmental basis of cold adaptation is key to understand how plants survive and adapt to different environmental conditions across their natural range. Univariate and multivariate genome-wide association (GWAS) and genotype-environment association (GEA) analyses were used to test associations among genome-wide SNPs obtained from whole-genome resequencing, measures of growth, phenology, emergence, cold hardiness, and range-wide environmental variation in coastal Douglas-fir (Pseudotsuga menziesii). Results suggest a complex genomic architecture of cold adaptation, in which traits are either highly polygenic or controlled by both large and small effect genes. Newly discovered associations for cold adaptation in Douglas-fir included 130 genes involved in many important biological functions such as primary and secondary metabolism, growth and reproductive development, transcription regulation, stress and signaling, and DNA processes. These genes were related to growth, phenology and cold hardiness and strongly depend on variation in environmental variables such degree days below 0c, precipitation, elevation and distance from the coast. This study is a step forward in our understanding of the complex interconnection between environment and genomics and their role in cold-associated trait variation in boreal tree species, providing a baseline for the species' predictions under climate change.
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Affiliation(s)
- Amanda R. De La Torre
- School of Forestry, Northern Arizona University, 200 E. Pine Knoll, Flagstaff, AZ 86011, USA;
| | - Benjamin Wilhite
- School of Forestry, Northern Arizona University, 200 E. Pine Knoll, Flagstaff, AZ 86011, USA;
| | - Daniela Puiu
- Center for Computational Biology, Department of Biomedical Engineering, Computer Science and Biostatistics, John Hopkins University, 3100 Wyman Park Dr, Wyman Park Building, Room S220, Baltimore, MD 21211, USA; (D.P.); (S.L.S.)
| | - John Bradley St. Clair
- USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR 97331, USA;
| | - Marc W. Crepeau
- Department of Evolution and Ecology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; (M.W.C.); (C.H.L.)
| | - Steven L. Salzberg
- Center for Computational Biology, Department of Biomedical Engineering, Computer Science and Biostatistics, John Hopkins University, 3100 Wyman Park Dr, Wyman Park Building, Room S220, Baltimore, MD 21211, USA; (D.P.); (S.L.S.)
| | - Charles H. Langley
- Department of Evolution and Ecology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; (M.W.C.); (C.H.L.)
| | - Brian Allen
- Department of Plant Sciences, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; (B.A.); (D.B.N.)
| | - David B. Neale
- Department of Plant Sciences, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; (B.A.); (D.B.N.)
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