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Rehman S, Bahadur S, Xia W. An overview of floral regulatory genes in annual and perennial plants. Gene 2023; 885:147699. [PMID: 37567454 DOI: 10.1016/j.gene.2023.147699] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/31/2023] [Accepted: 08/08/2023] [Indexed: 08/13/2023]
Abstract
The floral initiation in angiosperms is a complex process influenced by endogenous and exogenous signals. With this approach, we aim to provide a comprehensive review to integrate this complex floral regulatory process and summarize the regulatory genes and their functions in annuals and perennials. Seven primary paths leading to flowering have been discovered in Arabidopsis under several growth condition that include; photoperiod, ambient temperature, vernalization, gibberellins, autonomous, aging and carbohydrates. These pathways involve a series of interlinked signaling pathways that respond to both internal and external signals, such as light, temperature, hormones, and developmental cues, to coordinate the expression of genes that are involved in flower development. Among them, the photoperiodic pathway was the most important and conserved as some of the fundamental loci and mechanisms are shared even by closely related plant species. The activation of floral regulatory genes such as FLC, FT, LFY, and SOC1 that determine floral meristem identity and the transition to the flowering stage result from the merging of these pathways. Recent studies confirmed that alternative splicing, antisense RNA and epigenetic modification play crucial roles by regulating the expression of genes related to blooming. In this review, we documented recent progress in the floral transition time in annuals and perennials, with emphasis on the specific regulatory mechanisms along with the application of various molecular approaches including overexpression studies, RNA interference and Virus-induced flowering. Furthermore, the similarities and differences between annual and perennial flowering will aid significant contributions to the field by elucidating the mechanisms of perennial plant development and floral initiation regulation.
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Affiliation(s)
- Shazia Rehman
- Sanya Nanfan Research Institution, Hainan University, Haikou 572025, China; College of Tropical Crops, Hainan University, Haikou 570228, China
| | - Saraj Bahadur
- College of Forestry, Hainan University, Haikou 570228 China
| | - Wei Xia
- Sanya Nanfan Research Institution, Hainan University, Haikou 572025, China; College of Tropical Crops, Hainan University, Haikou 570228, China.
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2
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Wijnen CL, Becker FFM, Okkersen AA, de Snoo CB, Boer MP, van Eeuwijk FA, Wijnker E, Keurentjes JJB. Genetic Mapping of Genotype-by-Ploidy Effects in Arabidopsis thaliana. Genes (Basel) 2023; 14:1161. [PMID: 37372341 DOI: 10.3390/genes14061161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
Plants can express different phenotypic responses following polyploidization, but ploidy-dependent phenotypic variation has so far not been assigned to specific genetic factors. To map such effects, segregating populations at different ploidy levels are required. The availability of an efficient haploid inducer line in Arabidopsis thaliana allows for the rapid development of large populations of segregating haploid offspring. Because Arabidopsis haploids can be self-fertilised to give rise to homozygous doubled haploids, the same genotypes can be phenotyped at both the haploid and diploid ploidy level. Here, we compared the phenotypes of recombinant haploid and diploid offspring derived from a cross between two late flowering accessions to map genotype × ploidy (G × P) interactions. Ploidy-specific quantitative trait loci (QTLs) were detected at both ploidy levels. This implies that mapping power will increase when phenotypic measurements of monoploids are included in QTL analyses. A multi-trait analysis further revealed pleiotropic effects for a number of the ploidy-specific QTLs as well as opposite effects at different ploidy levels for general QTLs. Taken together, we provide evidence of genetic variation between different Arabidopsis accessions being causal for dissimilarities in phenotypic responses to altered ploidy levels, revealing a G × P effect. Additionally, by investigating a population derived from late flowering accessions, we revealed a major vernalisation-specific QTL for variation in flowering time, countering the historical bias of research in early flowering accessions.
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Affiliation(s)
- Cris L Wijnen
- Laboratory of Genetics, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Biometris, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Frank F M Becker
- Laboratory of Genetics, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Andries A Okkersen
- Laboratory of Genetics, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - C Bastiaan de Snoo
- Rijk Zwaan R&D Fijnaart, Eerste Kruisweg 9, 4793 RS Fijnaart, The Netherlands
| | - Martin P Boer
- Biometris, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Fred A van Eeuwijk
- Biometris, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Erik Wijnker
- Laboratory of Genetics, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Joost J B Keurentjes
- Laboratory of Genetics, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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3
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He F, Zhang F, Jiang X, Long R, Wang Z, Chen Y, Li M, Gao T, Yang T, Wang C, Kang J, Chen L, Yang Q. A Genome-Wide Association Study Coupled With a Transcriptomic Analysis Reveals the Genetic Loci and Candidate Genes Governing the Flowering Time in Alfalfa ( Medicago sativa L.). FRONTIERS IN PLANT SCIENCE 2022; 13:913947. [PMID: 35898229 PMCID: PMC9310038 DOI: 10.3389/fpls.2022.913947] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
The transition to flowering at the right time is very important for adapting to local conditions and maximizing alfalfa yield. However, the understanding of the genetic basis of the alfalfa flowering time remains limited. There are few reliable genes or markers for selection, which hinders progress in genetic research and molecular breeding of this trait in alfalfa. We sequenced 220 alfalfa cultivars and conducted a genome-wide association study (GWAS) involving 875,023 single-nucleotide polymorphisms (SNPs). The phenotypic analysis showed that the breeding status and geographical origin strongly influenced the alfalfa flowering time. Our GWAS revealed 63 loci significantly related to the flowering time. Ninety-five candidate genes were detected at these SNP loci within 40 kb (20 kb up- and downstream). Thirty-six percent of the candidate genes are involved in development and pollen tube growth, indicating that these genes are key genetic mechanisms of alfalfa growth and development. The transcriptomic analysis showed that 1,924, 2,405, and 3,779 differentially expressed genes (DEGs) were upregulated across the three growth stages, while 1,651, 2,613, and 4,730 DEGs were downregulated across the stages. Combining the results of our GWAS and transcriptome analysis, in total, 38 candidate genes (7 differentially expressed during the bud stage, 13 differentially expressed during the initial flowering stage, and 18 differentially expressed during the full flowering stage) were identified. Two SNPs located in the upstream region of the Msa0888690 gene (which is involved in isop renoids) were significantly related to flowering. The two significant SNPs within the upstream region of Msa0888690 existed as four different haplotypes in this panel. The genes identified in this study represent a series of candidate targets for further research investigating the alfalfa flowering time and could be used for alfalfa molecular breeding.
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Affiliation(s)
- Fei He
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fan Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xueqian Jiang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ruicai Long
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhen Wang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yishi Chen
- Center for Monitoring of Agricultural Ecological Environment and Quality Inspection of Agricultural Products of Tianjin, Tianjin, China
| | - Mingna Li
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ting Gao
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Tianhui Yang
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Chuan Wang
- Institute of Animal Science, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan, China
| | - Junmei Kang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lin Chen
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qingchuan Yang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
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4
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Distinct Cold Acclimation of Productivity Traits in Arabidopsis thaliana Ecotypes. Int J Mol Sci 2022; 23:ijms23042129. [PMID: 35216246 PMCID: PMC8879503 DOI: 10.3390/ijms23042129] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 12/10/2022] Open
Abstract
Improvement of crop climate resilience will require an understanding of whole-plant adaptation to specific local environments. This review places features of plant form and function related to photosynthetic productivity, as well as associated gene-expression patterns, into the context of the adaptation of Arabidopsis thaliana ecotypes to local environments with different climates in Sweden and Italy. The growth of plants under common cool conditions resulted in a proportionally greater emphasis on the maintenance of photosynthetic activity in the Swedish ecotype. This is compared to a greater emphasis on downregulation of light-harvesting antenna size and upregulation of a host of antioxidant enzymes in the Italian ecotype under these conditions. This differential response is discussed in the context of the climatic patterns of the ecotypes’ native habitats with substantial opportunity for photosynthetic productivity under mild temperatures in Italy but not in Sweden. The Swedish ecotype’s response is likened to pushing forward at full speed with productivity under low temperature versus the Italian ecotype’s response of staying safe from harm (maintaining redox homeostasis) while letting productivity decline when temperatures are transiently cold. It is concluded that either strategy can offer directions for the development of climate-resilient crops for specific locations of cultivation.
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Mirnezami SV, Srinivasan S, Zhou Y, Schnable PS, Ganapathysubramanian B. Detection of the Progression of Anthesis in Field-Grown Maize Tassels: A Case Study. PLANT PHENOMICS (WASHINGTON, D.C.) 2021; 2021:4238701. [PMID: 33728412 PMCID: PMC7953991 DOI: 10.34133/2021/4238701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 02/11/2021] [Indexed: 05/19/2023]
Abstract
The tassel of the maize plant is responsible for the production and dispersal of pollen for subsequent capture by the silk (stigma) and fertilization of the ovules. Both the amount and timing of pollen shed are physiological traits that impact the production of a hybrid seed. This study describes an automated end-to-end pipeline that combines deep learning and image processing approaches to extract tassel flowering patterns from time-lapse camera images of plants grown under field conditions. Inbred lines from the SAM and NAM diversity panels were grown at the Curtiss farm at Iowa State University, Ames, IA, during the summer of 2016. Using a set of around 500 pole-mounted cameras installed in the field, images of plants were captured every 10 minutes of daylight hours over a three-week period. Extracting data from imaging performed under field conditions is challenging due to variabilities in weather, illumination, and the morphological diversity of tassels. To address these issues, deep learning algorithms were used for tassel detection, classification, and segmentation. Image processing approaches were then used to crop the main spike of the tassel to track reproductive development. The results demonstrated that deep learning with well-labeled data is a powerful tool for detecting, classifying, and segmenting tassels. Our sequential workflow exhibited the following metrics: mAP for tassel detection was 0.91, F1 score obtained for tassel classification was 0.93, and accuracy of semantic segmentation in creating a binary image from the RGB tassel images was 0.95. This workflow was used to determine spatiotemporal variations in the thickness of the main spike-which serves as a proxy for anthesis progression.
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Affiliation(s)
| | - Srikant Srinivasan
- Department of Agronomy, Iowa State University, Ames, Iowa 50011, USA
- School of Computing and Electrical Engineering, Indian Institute of Technology Mandi, Kamand, H.P., India
| | - Yan Zhou
- Department of Agronomy, Iowa State University, Ames, Iowa 50011, USA
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6
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Tudor EH, Jones DM, He Z, Bancroft I, Trick M, Wells R, Irwin JA, Dean C. QTL-seq identifies BnaFT.A02 and BnaFLC.A02 as candidates for variation in vernalization requirement and response in winter oilseed rape (Brassica napus). PLANT BIOTECHNOLOGY JOURNAL 2020; 18:2466-2481. [PMID: 32452611 PMCID: PMC7680531 DOI: 10.1111/pbi.13421] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/10/2020] [Accepted: 05/11/2020] [Indexed: 05/05/2023]
Abstract
Winter, spring and biennial varieties of Brassica napus that vary in vernalization requirement are grown for vegetable and oil production. Here, we show that the obligate or facultative nature of the vernalization requirement in European winter oilseed rape is determined by allelic variation at a 10 Mbp region on chromosome A02. This region includes orthologues of the key floral regulators FLOWERING LOCUS C (BnaFLC.A02) and FLOWERING LOCUS T (BnaFT.A02). Polymorphism at BnaFLC.A02 and BnaFT.A02, mostly in cis-regulatory regions, results in distinct gene expression dynamics in response to vernalization treatment. Our data suggest allelic variation at BnaFT.A02 is associated with flowering time in the absence of vernalization, while variation at BnaFLC.A02 is associated with flowering time under vernalizing conditions. We hypothesize selection for BnaFLC.A02 and BnaFT.A02 gene expression variation has facilitated the generation of European winter oilseed rape varieties that are adapted to different winter climates. This knowledge will allow for the selection of alleles of flowering time regulators that alter the vernalization requirement of oilseed rape, informing the generation of new varieties with adapted flowering times and improved yields.
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Affiliation(s)
| | | | - Zhesi He
- Department of BiologyUniversity of YorkYorkUK
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7
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Hepworth J, Antoniou-Kourounioti RL, Berggren K, Selga C, Tudor EH, Yates B, Cox D, Collier Harris BR, Irwin JA, Howard M, Säll T, Holm S, Dean C. Natural variation in autumn expression is the major adaptive determinant distinguishing Arabidopsis FLC haplotypes. eLife 2020; 9:57671. [PMID: 32902380 PMCID: PMC7518893 DOI: 10.7554/elife.57671] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/08/2020] [Indexed: 12/27/2022] Open
Abstract
In Arabidopsis thaliana, winter is registered during vernalization through the temperature-dependent repression and epigenetic silencing of floral repressor FLOWERING LOCUS C (FLC). Natural Arabidopsis accessions show considerable variation in vernalization. However, which aspect of the FLC repression mechanism is most important for adaptation to different environments is unclear. By analysing FLC dynamics in natural variants and mutants throughout winter in three field sites, we find that autumnal FLC expression, rather than epigenetic silencing, is the major variable conferred by the distinct Arabidopsis FLChaplotypes. This variation influences flowering responses of Arabidopsis accessions resulting in an interplay between promotion and delay of flowering in different climates to balance survival and, through a post-vernalization effect, reproductive output. These data reveal how expression variation through non-coding cis variation at FLC has enabled Arabidopsis accessions to adapt to different climatic conditions and year-on-year fluctuations.
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Affiliation(s)
- Jo Hepworth
- Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | | | - Kristina Berggren
- Department of Natural Sciences, Mid Sweden University, Sundsvall, Sweden
| | - Catja Selga
- Department of Biology, Lund University, Lund, Sweden
| | - Eleri H Tudor
- Crop Genetics, John Innes Centre, Norwich, United Kingdom
| | - Bryony Yates
- Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Deborah Cox
- Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | | | - Judith A Irwin
- Crop Genetics, John Innes Centre, Norwich, United Kingdom
| | - Martin Howard
- Computational and Systems Biology, John Innes Centre, Norwich, United Kingdom
| | - Torbjörn Säll
- Department of Biology, Lund University, Lund, Sweden
| | - Svante Holm
- Department of Natural Sciences, Mid Sweden University, Sundsvall, Sweden
| | - Caroline Dean
- Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
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Miryeganeh M. Synchronization of senescence and desynchronization of flowering in Arabidopsis thaliana. AOB PLANTS 2020; 12:plaa018. [PMID: 32577195 PMCID: PMC7299267 DOI: 10.1093/aobpla/plaa018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
In a recent publication, we proposed that adjusting lifespan in order to synchronize senescence is important for timing of reproduction, and we quantified the synchrony of reproductive timing relative to germination timing. Here, in a second sequential seeding experiment (SSE), the germination timing of Arabidopsis thaliana accessions was manipulated and plants were then grown under two different temperature regimes. Life stage traits of plants in each temperature regime were analysed and it was evaluated whether the cohorts were grouped according to age and/or environmental conditions. While flowering-related traits showed desynchrony among cohorts, striking synchrony in the timing of senescence among cohorts for each group was found. A quantitative trait locus (QTL) analysis using a genotyped population of 'Cvi/Ler' recombinant inbred lines (RILs) was then conducted. Novel and known loci were assigned to flowering and senescence timing. However, senescence synchrony resulted in low variation in senescence time and weak QTL detection for flowering termination. Overlapping flowering and senescence genes with loci affecting either of those traits were found and suggest a potential interdependency of reproductive traits.
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Affiliation(s)
- Matin Miryeganeh
- Center for Ecological Research, Kyoto University, Hirano, Otsu, Japan
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9
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Marshall MM, Remington DL, Lacey EP. Two reproductive traits show contrasting genetic architectures in Plantago lanceolata. Mol Ecol 2019; 29:272-291. [PMID: 31793079 DOI: 10.1111/mec.15320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/25/2022]
Abstract
In many species, temperature-sensitive phenotypic plasticity (i.e., an individual's phenotypic response to temperature) displays a positive correlation with latitude, a pattern presumed to reflect local adaptation. This geographical pattern raises two general questions: (a) Do a few large-effect genes contribute to latitudinal variation in a trait? (b) Is the thermal plasticity of different traits regulated pleiotropically? To address the questions, we crossed individuals of Plantago lanceolata derived from northern and southern European populations. Individuals naturally exhibited high and low thermal plasticity in floral reflectance and flowering time. We grew parents and offspring in controlled cool- and warm-temperature environments, mimicking what plants would encounter in nature. We obtained genetic markers via genotype-by-sequencing, produced the first recombination map for this ecologically important nonmodel species, and performed quantitative trait locus (QTL) mapping of thermal plasticity and single-environment values for both traits. We identified a large-effect QTL that largely explained the reflectance plasticity differences between northern and southern populations. We identified multiple smaller-effect QTLs affecting aspects of flowering time, one of which affected flowering time plasticity. The results indicate that the genetic architecture of thermal plasticity in flowering is more complex than for reflectance. One flowering time QTL showed strong cytonuclear interactions under cool temperatures. Reflectance and flowering plasticity QTLs did not colocalize, suggesting little pleiotropic genetic control and freedom for independent trait evolution. Such genetic information about the architecture of plasticity is environmentally important because it informs us about the potential for plasticity to offset negative effects of climate change.
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Affiliation(s)
- Matthew M Marshall
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - David L Remington
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Elizabeth P Lacey
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, USA
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Adhikari L, Makaju SO, Missaoui AM. QTL mapping of flowering time and biomass yield in tetraploid alfalfa (Medicago sativa L.). BMC PLANT BIOLOGY 2019; 19:359. [PMID: 31419945 PMCID: PMC6697951 DOI: 10.1186/s12870-019-1946-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 07/26/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND The genetic and genomic basis of flowering time and biomass yield in alfalfa (Medicago sativa L.) remains poorly understood mainly due to the autopolyploid nature of the species and the lack of adequate genomic resources. We constructed linkage maps using genotyping-by-sequencing (GBS) based single dose allele (SDA) SNP and mapped alfalfa timing of flowering (TOF), spring yield (SY), and cumulative summer biomass (CSB) in a pseudo-testcross F1 population derived from a fall dormant (3010) and a non-dormant (CW 1010) cultivars. We analyzed the quantitative trait loci (QTL) to identify conserved genomic regions and detected molecular markers and potential candidate genes associated with the traits to improve alfalfa and provide genomic resources for the future studies. RESULTS This study showed that both fall dormant and non-dormant alfalfa cultivars harbored QTL for early and late flowering, suggesting that flowering time in alfalfa is not an indicator of its fall dormancy (FD) levels. A weak phenotypic correlation between the flowering time and fall dormancy (FD) in F1 and checks also corroborated that alfalfa FD and TOF are not the predictors of one another. The relationship between flowering time and alfalfa biomass yield was not strong, but the non-dormant had relatively more SY than dormant. Therefore, selecting superior alfalfa cultivars that are non-dormant, winter-hardy, and early flowering would allow for an early spring harvest with enhanced biomass. In this study, we found 25 QTL for TOF, 17 for SY and six QTL for CSB. Three TOF related QTL were stable and four TOF QTL were detected in the corresponding genomic locations of the flowering QTL of M. truncatula, an indication of possible evolutionarily conserved regions. The potential candidate genes for the SNP sequences of QTL regions were identified for all three traits and these genes would be potential targets for further molecular studies. CONCLUSIONS This research showed that variation in alfalfa flowering time after spring green up has no association with dormancy levels. Here we reported QTL, markers, and potential candidate genes associated with spring flowering time and biomass yield of alfalfa, which constitute valuable genomic resources for improving these traits via marker-assisted selection (MAS).
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Affiliation(s)
- Laxman Adhikari
- Institute of Plant Breeding, Genetics and Genomics and Department of Crop and Soil Sciences, The University of Georgia, Athens, GA, USA
| | - Shiva Om Makaju
- Institute of Plant Breeding, Genetics and Genomics and Department of Crop and Soil Sciences, The University of Georgia, Athens, GA, USA
| | - Ali M Missaoui
- Institute of Plant Breeding, Genetics and Genomics and Department of Crop and Soil Sciences, The University of Georgia, Athens, GA, USA.
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11
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Abuyusuf M, Nath UK, Kim HT, Islam MR, Park JI, Nou IS. Molecular markers based on sequence variation in BoFLC1.C9 for characterizing early- and late-flowering cabbage genotypes. BMC Genet 2019; 20:42. [PMID: 31029104 PMCID: PMC6487051 DOI: 10.1186/s12863-019-0740-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 03/18/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cabbage (Brassica oleracea var. capitata) is popular worldwide for consumption as a leafy vegetable. Premature flowering is triggered by low temperature, and deteriorates quality of cabbage as vegetable. In general, growers prefer late-flowering varieties to assure good quality compact head. Here, we report BoFLC1.C9 as a gene with clear sequence variation between cabbage lines with different flowering times, and proposed as molecular marker to characterize early- and late-flowering cabbage lines. RESULTS We identified sequence variation of 67 bp insertions in intron 2, which were contributed in flowering time variation between two inbred lines through rapid down-regulation of the BoFLC1.C9 gene in early-flowering line compared to late-flowering one upon vernalization. One set of primer 'F7R7' proposed as marker, of which was explained with 83 and 80% of flowering time variation in 141 F2 individuals and 20 commercial lines, respectively. CONCLUSIONS This F7R7 marker could be used as genetic tools to characterize flowering time variation and to select as well to develop early- and late-flowering cabbage cultivars.
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Affiliation(s)
- Md Abuyusuf
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea.,Department of Agronomy, Patuakhali Science and Technology University, Patuakhali, 8602, Bangladesh
| | - Ujjal Kumar Nath
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea.,Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
| | - Hoy-Taek Kim
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea.,University-Industry Cooperation Foundation, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea
| | - Md Rafiqul Islam
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea
| | - Jong-In Park
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea.
| | - Ill-Sup Nou
- Department of Horticulture, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam, 57922, Republic of Korea.
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12
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Marchadier E, Hanemian M, Tisné S, Bach L, Bazakos C, Gilbault E, Haddadi P, Virlouvet L, Loudet O. The complex genetic architecture of shoot growth natural variation in Arabidopsis thaliana. PLoS Genet 2019; 15:e1007954. [PMID: 31009456 PMCID: PMC6476473 DOI: 10.1371/journal.pgen.1007954] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 01/11/2019] [Indexed: 12/16/2022] Open
Abstract
One of the main outcomes of quantitative genetics approaches to natural variation is to reveal the genetic architecture underlying the phenotypic space. Complex genetic architectures are described as including numerous loci (or alleles) with small-effect and/or low-frequency in the populations, interactions with the genetic background, environment or age. Linkage or association mapping strategies will be more or less sensitive to this complexity, so that we still have an unclear picture of its extent. By combining high-throughput phenotyping under two environmental conditions with classical QTL mapping approaches in multiple Arabidopsis thaliana segregating populations as well as advanced near isogenic lines construction and survey, we have attempted to improve our understanding of quantitative phenotypic variation. Integrative traits such as those related to vegetative growth used in this work (highlighting either cumulative growth, growth rate or morphology) all showed complex and dynamic genetic architecture with respect to the segregating population and condition. The more resolutive our mapping approach, the more complexity we uncover, with several instances of QTLs visible in near isogenic lines but not detected with the initial QTL mapping, indicating that our phenotyping accuracy was less limiting than the mapping resolution with respect to the underlying genetic architecture. In an ultimate approach to resolve this complexity, we intensified our phenotyping effort to target specifically a 3Mb-region known to segregate for a major quantitative trait gene, using a series of selected lines recombined every 100kb. We discovered that at least 3 other independent QTLs had remained hidden in this region, some with trait- or condition-specific effects, or opposite allelic effects. If we were to extrapolate the figures obtained on this specific region in this particular cross to the genome- and species-scale, we would predict hundreds of causative loci of detectable phenotypic effect controlling these growth-related phenotypes.
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Affiliation(s)
- Elodie Marchadier
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Mathieu Hanemian
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Sébastien Tisné
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Liên Bach
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Christos Bazakos
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Elodie Gilbault
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Parham Haddadi
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Laetitia Virlouvet
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Olivier Loudet
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
- * E-mail:
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Su T, Wang W, Li P, Zhang B, Li P, Xin X, Sun H, Yu Y, Zhang D, Zhao X, Wen C, Zhou G, Wang Y, Zheng H, Yu S, Zhang F. A Genomic Variation Map Provides Insights into the Genetic Basis of Spring Chinese Cabbage (Brassica rapa ssp. pekinensis) Selection. MOLECULAR PLANT 2018; 11:1360-1376. [PMID: 30217779 DOI: 10.1016/j.molp.2018.08.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 08/22/2018] [Accepted: 08/31/2018] [Indexed: 05/08/2023]
Abstract
Chinese cabbage is the most consumed leafy crop in East Asian countries. However, premature bolting induced by continuous low temperatures severely decreases the yield and quality of the Chinese cabbage, and therefore restricts its planting season and geographic distribution. In the past 40 years, spring Chinese cabbage with strong winterness has been selected to meet the market demand. Here, we report a genome variation map of Chinese cabbage generated from the resequencing data of 194 geographically diverse accessions of three ecotypes. In-depth analyses of the selection sweeps and genome-wide patterns revealed that spring Chinese cabbage was selected from a specific population of autumn Chinese cabbage around the area of Shandong peninsula in northern China. We identified 23 genomic loci that underwent intensive selection, and further demonstrated by gene expression and haplotype analyses that the incorporation of elite alleles of VERNALISATION INSENTIVE 3.1 (BrVIN3.1) and FLOWER LOCUS C 1 (BrFLC1) is a determinant genetic source of variation during selection. Moreover, we showed that the quantitative response of BrVIN3.1 to cold due to the sequence variations in the cis elements of the BrVIN3.1 promoter significantly contributes to bolting-time variation in Chinese cabbage. Collectively, our study provides valuable insights into the genetic basis of spring Chinese cabbage selection and will facilitate the breeding of bolting-resistant varieties by molecular-marker-assisted selection, transgenic or gene editing approaches.
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Affiliation(s)
- Tongbing Su
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, UK; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Weihong Wang
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Peirong Li
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Bin Zhang
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Pan Li
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China
| | - Xiaoyun Xin
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China
| | - Honghe Sun
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Yangjun Yu
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Deshuang Zhang
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Xiuyun Zhao
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Changlong Wen
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Gang Zhou
- Biomarker Technologies Corporation, Beijing, China
| | - Yuntong Wang
- Biomarker Technologies Corporation, Beijing, China
| | | | - Shuancang Yu
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China.
| | - Fenglan Zhang
- Beijing Vegetable Research Center (BVRC), Beijing Academy of Agriculture and Forestry Science (BAAFS), Beijing 100097, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing 100097, China; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China.
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Theißen G, Rümpler F, Gramzow L. Array of MADS-Box Genes: Facilitator for Rapid Adaptation? TRENDS IN PLANT SCIENCE 2018; 23:563-576. [PMID: 29802068 DOI: 10.1016/j.tplants.2018.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 05/18/2023]
Abstract
In a world of global warming, the question emerges whether all plants have suitable mechanisms to keep pace with the rapidly changing environment. Most previous studies have focused on either the ability of plants to rapidly acclimatize via physiological and developmental plasticity, or long-term adaptation over thousands of years. However, we wonder whether plants can also adapt to changes in the environment within only a few generations. We hypothesize that rapidly evolving clusters of tandemly duplicated developmental control genes represent a source for fast adaptation. Specifically, we propose that a tandem cluster of FLC-like MADS-box genes involved in the transition to flowering in Arabidopsis functions as a facilitator for rapid adaptation to changes in ambient temperature.
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Affiliation(s)
- Günter Theißen
- Friedrich Schiller University Jena, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Philosophenweg 12, D-07743 Jena, Germany.
| | - Florian Rümpler
- Friedrich Schiller University Jena, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Philosophenweg 12, D-07743 Jena, Germany
| | - Lydia Gramzow
- Friedrich Schiller University Jena, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Philosophenweg 12, D-07743 Jena, Germany
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15
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Bahri BA, Daverdin G, Xu X, Cheng JF, Barry KW, Brummer EC, Devos KM. Natural variation in genes potentially involved in plant architecture and adaptation in switchgrass (Panicum virgatum L.). BMC Evol Biol 2018; 18:91. [PMID: 29898656 PMCID: PMC6000970 DOI: 10.1186/s12862-018-1193-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 05/15/2018] [Indexed: 11/24/2022] Open
Abstract
Background Advances in genomic technologies have expanded our ability to accurately and exhaustively detect natural genomic variants that can be applied in crop improvement and to increase our knowledge of plant evolution and adaptation. Switchgrass (Panicum virgatum L.), an allotetraploid (2n = 4× = 36) perennial C4 grass (Poaceae family) native to North America and a feedstock crop for cellulosic biofuel production, has a large potential for genetic improvement due to its high genotypic and phenotypic variation. In this study, we analyzed single nucleotide polymorphism (SNP) variation in 372 switchgrass genotypes belonging to 36 accessions for 12 genes putatively involved in biomass production to investigate signatures of selection that could have led to ecotype differentiation and to population adaptation to geographic zones. Results A total of 11,682 SNPs were mined from ~ 15 Gb of sequence data, out of which 251 SNPs were retained after filtering. Population structure analysis largely grouped upland accessions into one subpopulation and lowland accessions into two additional subpopulations. The most frequent SNPs were in homozygous state within accessions. Sixty percent of the exonic SNPs were non-synonymous and, of these, 45% led to non-conservative amino acid changes. The non-conservative SNPs were largely in linkage disequilibrium with one haplotype being predominantly present in upland accessions while the other haplotype was commonly present in lowland accessions. Tajima’s test of neutrality indicated that PHYB, a gene involved in photoperiod response, was under positive selection in the switchgrass population. PHYB carried a SNP leading to a non-conservative amino acid change in the PAS domain, a region that acts as a sensor for light and oxygen in signal transduction. Conclusions Several non-conservative SNPs in genes potentially involved in plant architecture and adaptation have been identified and led to population structure and genetic differentiation of ecotypes in switchgrass. We suggest here that PHYB is a key gene involved in switchgrass natural selection. Further analyses are needed to determine whether any of the non-conservative SNPs identified play a role in the differential adaptation of upland and lowland switchgrass. Electronic supplementary material The online version of this article (10.1186/s12862-018-1193-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bochra A Bahri
- Institute of Plant Breeding, Genetics and Genomics (Department of Crop and Soil Sciences), and Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA. .,Laboratory of Bioaggressors and Integrated Protection in Agriculture, The National Agronomic Institute of Tunisia, University of Carthage, 43 Avenue Charles-Nicolle, 1082, Tunis, Tunisia.
| | - Guillaume Daverdin
- Institute of Plant Breeding, Genetics and Genomics (Department of Crop and Soil Sciences), and Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA.,Present address: Vinson Edward Ltd, Faversham, ME13 8UP, UK
| | - Xiangyang Xu
- Institute of Plant Breeding, Genetics and Genomics (Department of Crop and Soil Sciences), and Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA.,Present address: USDA-ARS, Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK, 74075, USA
| | - Jan-Fang Cheng
- DOE Joint Genome Institute, Walnut Creek, California, CA, 94598, USA
| | - Kerrie W Barry
- DOE Joint Genome Institute, Walnut Creek, California, CA, 94598, USA
| | - E Charles Brummer
- Plant Breeding Center, Plant Sciences Department, University of California, Davis, CA, 95616, USA
| | - Katrien M Devos
- Institute of Plant Breeding, Genetics and Genomics (Department of Crop and Soil Sciences), and Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
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16
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Optimization of Photosynthetic Productivity in Contrasting Environments by Regulons Controlling Plant Form and Function. Int J Mol Sci 2018; 19:ijms19030872. [PMID: 29543762 PMCID: PMC5877733 DOI: 10.3390/ijms19030872] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/13/2018] [Accepted: 03/13/2018] [Indexed: 01/06/2023] Open
Abstract
We review the role of a family of transcription factors and their regulons in maintaining high photosynthetic performance across a range of challenging environments with a focus on extreme temperatures and water availability. Specifically, these transcription factors include CBFs (C-repeat binding factors) and DREBs (dehydration-responsive element-binding), with CBF/DREB1 primarily orchestrating cold adaptation and other DREBs serving in heat, drought, and salinity adaptation. The central role of these modulators in plant performance under challenging environments is based on (i) interweaving of these regulators with other key signaling networks (plant hormones and redox signals) as well as (ii) their function in integrating responses across the whole plant, from light-harvesting and sugar-production in the leaf to foliar sugar export and water import and on to the plant's sugar-consuming sinks (growth, storage, and reproduction). The example of Arabidopsisthaliana ecotypes from geographic origins with contrasting climates is used to describe the links between natural genetic variation in CBF transcription factors and the differential acclimation of plant anatomical and functional features needed to support superior photosynthetic performance in contrasting environments. Emphasis is placed on considering different temperature environments (hot versus cold) and light environments (limiting versus high light), on trade-offs between adaptations to contrasting environments, and on plant lines minimizing such trade-offs.
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17
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Stewart JJ, Polutchko SK, Adams WW, Demmig-Adams B. Acclimation of Swedish and Italian ecotypes of Arabidopsis thaliana to light intensity. PHOTOSYNTHESIS RESEARCH 2017; 134:215-229. [PMID: 28861679 DOI: 10.1007/s11120-017-0436-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 08/22/2017] [Indexed: 05/22/2023]
Abstract
This study addressed whether ecotypes of Arabidopsis thaliana from Sweden and Italy exhibited differences in foliar acclimation to high versus low growth light intensity, and compared CO2 uptake under growth conditions with light- and CO2-saturated intrinsic photosynthetic capacity and leaf morphological and vascular features. Differential responses between ecotypes occurred mainly at the scale of leaf architecture, with thicker leaves with higher intrinsic photosynthetic capacities and chlorophyll contents per leaf area, but no difference in photosynthetic capacity on a chlorophyll basis, in high light-grown leaves of the Swedish versus the Italian ecotype. Greater intrinsic photosynthetic capacity per leaf area in the Swedish ecotype was accompanied by a greater capacity of vascular infrastructure for sugar and water transport, but this was not associated with greater CO2 uptake rates under growth conditions. The Swedish ecotype with its thick leaves is thus constructed for high intrinsic photosynthetic and vascular flux capacity even under growth chamber conditions that may not permit full utilization of this potential. Conversely, the Swedish ecotype was less tolerant of low growth light intensity than the Italian ecotype, with smaller rosette areas and lesser aboveground biomass accumulation in low light-grown plants. Foliar vein density and stomatal density were both enhanced by high growth light intensity with no significant difference between ecotypes, and the ratio of water to sugar conduits was also similar between the two ecotypes during light acclimation. These findings add to the understanding of the foliar vasculature's role in plant photosynthetic acclimation and adaptation.
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Affiliation(s)
- Jared J Stewart
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Stephanie K Polutchko
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - William W Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Barbara Demmig-Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
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18
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Abstract
Our understanding of the detailed molecular mechanisms underpinning adaptation is still poor. One example for which mechanistic understanding of regulation has converged with studies of life history variation is Arabidopsis thaliana FLOWERING LOCUS C (FLC). FLC determines the need for plants to overwinter and their ability to respond to prolonged cold in a process termed vernalization. This review highlights how molecular analysis of vernalization pathways has revealed important insight into antisense-mediated chromatin silencing mechanisms that regulate FLC. In turn, such insight has enabled molecular dissection of the diversity in vernalization across natural populations of A. thaliana. Changes in both cotranscriptional regulation and epigenetic silencing of FLC are caused by noncoding polymorphisms at FLC. The FLC locus is therefore providing important concepts for how noncoding transcription and chromatin regulation influence gene expression and how these mechanisms can vary to underpin adaptation in natural populations.
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Affiliation(s)
- Charles Whittaker
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom;
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom;
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19
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Fernández-Mazuecos M, Glover BJ. The evo-devo of plant speciation. Nat Ecol Evol 2017; 1:110. [DOI: 10.1038/s41559-017-0110] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/07/2017] [Indexed: 11/09/2022]
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20
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Schiessl S, Huettel B, Kuehn D, Reinhardt R, Snowdon R. Post-polyploidisation morphotype diversification associates with gene copy number variation. Sci Rep 2017; 7:41845. [PMID: 28165502 PMCID: PMC5292959 DOI: 10.1038/srep41845] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/03/2017] [Indexed: 11/24/2022] Open
Abstract
Genetic models for polyploid crop adaptation provide important information relevant for future breeding prospects. A well-suited model is Brassica napus, a recent allopolyploid closely related to Arabidopsis thaliana. Flowering time is a major adaptation trait determining life cycle synchronization with the environment. Here we unravel natural genetic variation in B. napus flowering time regulators and investigate associations with evolutionary diversification into different life cycle morphotypes. Deep sequencing of 35 flowering regulators was performed in 280 diverse B. napus genotypes. High sequencing depth enabled high-quality calling of single-nucleotide polymorphisms (SNPs), insertion-deletions (InDels) and copy number variants (CNVs). By combining these data with genotyping data from the Brassica 60 K Illumina® Infinium SNP array, we performed a genome-wide marker distribution analysis across the 4 ecogeographical morphotypes. Twelve haplotypes, including Bna.FLC.A10, Bna.VIN3.A02 and the Bna.FT promoter on C02_random, were diagnostic for the diversification of winter and spring types. The subspecies split between oilseed/kale (B. napus ssp. napus) and swedes/rutabagas (B. napus ssp. napobrassica) was defined by 13 haplotypes, including genomic rearrangements encompassing copies of Bna.FLC, Bna.PHYA and Bna.GA3ox1. De novo variation in copies of important flowering-time genes in B. napus arose during allopolyploidisation, enabling sub-functionalisation that allowed different morphotypes to appropriately fine-tune their lifecycle.
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Affiliation(s)
- Sarah Schiessl
- Department of Plant Breeding, Justus Liebig University, IFZ Research Centre for Biosystems, Land Use and Nutrition, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Bruno Huettel
- Max Planck Institute for Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Diana Kuehn
- Max Planck Institute for Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Richard Reinhardt
- Max Planck Institute for Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Rod Snowdon
- Department of Plant Breeding, Justus Liebig University, IFZ Research Centre for Biosystems, Land Use and Nutrition, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
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21
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Ågren J, Oakley CG, Lundemo S, Schemske DW. Adaptive divergence in flowering time among natural populations of
Arabidopsis thaliana
: Estimates of selection and QTL mapping. Evolution 2016; 71:550-564. [DOI: 10.1111/evo.13126] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/27/2016] [Accepted: 10/31/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Jon Ågren
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre Uppsala University Norbyvägen 18 D SE‐752 36 Uppsala Sweden
| | | | - Sverre Lundemo
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre Uppsala University Norbyvägen 18 D SE‐752 36 Uppsala Sweden
- WWF Norway Postboks 6784, St. Olavs Plass 0130 Oslo Norway
| | - Douglas W. Schemske
- Department of Plant Biology and W. K. Kellogg Biological Station Michigan State University East Lansing Michigan 48824
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22
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Yuan W, Flowers JM, Sahraie DJ, Ehrenreich IM, Purugganan MD. Extreme QTL mapping of germination speed in Arabidopsis thaliana. Mol Ecol 2016; 25:4177-96. [DOI: 10.1111/mec.13768] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Wei Yuan
- Department of Biology; Center for Genomics and Systems Biology; New York University; 12 Waverly Place New York NY 10003 USA
| | - Jonathan M. Flowers
- Department of Biology; Center for Genomics and Systems Biology; New York University; 12 Waverly Place New York NY 10003 USA
- Center for Genomics and Systems Biology; NYU Abu Dhabi Research Institute; New York University Abu Dhabi; Saadiyat Island Abu Dhabi United Arab Emirates
| | - Dustin J. Sahraie
- Department of Biology; Center for Genomics and Systems Biology; New York University; 12 Waverly Place New York NY 10003 USA
| | - Ian M. Ehrenreich
- Molecular and Computational Biology Section; University of Southern California; Ray R. Irani Hall 201 Los Angeles CA 90089-2910 USA
| | - Michael D. Purugganan
- Department of Biology; Center for Genomics and Systems Biology; New York University; 12 Waverly Place New York NY 10003 USA
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23
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Adams WW, Stewart JJ, Cohu CM, Muller O, Demmig-Adams B. Habitat Temperature and Precipitation of Arabidopsis thaliana Ecotypes Determine the Response of Foliar Vasculature, Photosynthesis, and Transpiration to Growth Temperature. FRONTIERS IN PLANT SCIENCE 2016; 7:1026. [PMID: 27504111 PMCID: PMC4959142 DOI: 10.3389/fpls.2016.01026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 06/30/2016] [Indexed: 05/20/2023]
Abstract
Acclimatory adjustments of foliar vascular architecture, photosynthetic capacity, and transpiration rate in Arabidopsis thaliana ecotypes (Italian, Polish [Col-0], Swedish) were characterized in the context of habitat of origin. Temperatures of the habitat of origin decreased linearly with increasing habitat latitude, but habitat precipitation was greatest in Italy, lowest in Poland, and intermediate in Sweden. Plants of the three ecotypes raised under three different growth temperature regimes (low, moderate, and high) exhibited highest photosynthetic capacities, greatest leaf thickness, highest chlorophyll a/b ratio and levels of β-carotene, and greatest levels of wall ingrowths in phloem transfer cells, and, in the Col-0 and Swedish ecotypes, of phloem per minor vein in plants grown at the low temperature. In contrast, vein density and minor vein tracheary to sieve element ratio increased with increasing growth temperature - most strongly in Col-0 and least strongly in the Italian ecotype - and transpirational water loss correlated with vein density and number of tracheary elements per minor vein. Plotting of these vascular features as functions of climatic conditions in the habitat of origin suggested that temperatures during the evolutionary history of the ecotypes determined acclimatory responses of the foliar phloem and photosynthesis to temperature in this winter annual that upregulates photosynthesis in response to lower temperature, whereas the precipitation experienced during the evolutionary history of the ecotypes determined adjustment of foliar vein density, xylem, and transpiration to temperature. In particular, whereas photosynthetic capacity, leaf thickness, and foliar minor vein phloem features increased linearly with increasing latitude and decreasing temperature of the habitats of origin in response to experimental growth at low temperature, transpiration rate, foliar vein density, and minor vein tracheary element numbers and cross-sectional areas increased linearly with decreasing precipitation level in the habitats of origin in response to experimental growth at high temperature. This represents a situation where temperature acclimation of the apparent capacity for water flux through the xylem and transpiration rate in a winter annual responded differently from that of photosynthetic capacity, in contrast to previous reports of strong relationships between hydraulic conductance and photosynthesis in other studies.
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Affiliation(s)
- William W. Adams
- Department of Ecology and Evolutionary Biology, University of Colorado BoulderBoulder, CO, USA
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24
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Stewart JJ, Demmig-Adams B, Cohu CM, Wenzl CA, Muller O, Adams WW. Growth temperature impact on leaf form and function in Arabidopsis thaliana ecotypes from northern and southern Europe. PLANT, CELL & ENVIRONMENT 2016; 39:1549-58. [PMID: 26832121 DOI: 10.1111/pce.12720] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 01/17/2016] [Accepted: 01/18/2016] [Indexed: 05/25/2023]
Abstract
The plasticity of leaf form and function in European lines of Arabidopsis thaliana was evaluated in ecotypes from Sweden and Italy grown under contrasting (cool versus hot) temperature regimes. Although both ecotypes exhibited acclimatory adjustments, the Swedish ecotype exhibited more pronounced responses to the two contrasting temperature regimes in several characterized features. These responses included thicker leaves with higher capacities for photosynthesis, likely facilitated by a greater number of phloem cells per minor vein for the active loading and export of sugars, when grown under cool temperature as opposed to leaves with a higher vein density and a greater number of tracheary elements per minor vein, likely facilitating higher rates of transpirational water loss (and thus evaporative cooling), when grown under hot temperature with high water availability. In addition, only the Swedish ecotype exhibited reduced rosette growth and greater levels of foliar tocopherols under the hot growth temperature. These responses, and the greater responsiveness of the Swedish ecotype compared with the Italian ecotype, are discussed in the context of redox signalling networks and transcription factors, and the greater range of environmental conditions experienced by the Swedish versus the Italian ecotype during the growing season in their native habitats.
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Affiliation(s)
- Jared J Stewart
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Barbara Demmig-Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Christopher M Cohu
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Coleman A Wenzl
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Onno Muller
- Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Jülich, 52425, Germany
| | - William W Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
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Migicovsky Z, Gardner KM, Money D, Sawler J, Bloom JS, Moffett P, Chao CT, Schwaninger H, Fazio G, Zhong GY, Myles S. Genome to Phenome Mapping in Apple Using Historical Data. THE PLANT GENOME 2016; 9. [PMID: 27898813 DOI: 10.3835/plantgenome2015.11.0113] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Apple ( X Borkh.) is one of the world's most valuable fruit crops. Its large size and long juvenile phase make it a particularly promising candidate for marker-assisted selection (MAS). However, advances in MAS in apple have been limited by a lack of phenotype and genotype data from sufficiently large samples. To establish genotype-phenotype relationships and advance MAS in apple, we extracted over 24,000 phenotype scores from the USDA-Germplasm Resources Information Network (GRIN) database and linked them with over 8000 single nucleotide polymorphisms (SNPs) from 689 apple accessions from the USDA apple germplasm collection clonally preserved in Geneva, NY. We find significant genetic differentiation between Old World and New World cultivars and demonstrate that the genetic structure of the domesticated apple also reflects the time required for ripening. A genome-wide association study (GWAS) of 36 phenotypes confirms the association between fruit color and the MYB1 locus, and we also report a novel association between the transcription factor, NAC18.1, and harvest date and fruit firmness. We demonstrate that harvest time and fruit size can be predicted with relatively high accuracies ( > 0.46) using genomic prediction. Rapid decay of linkage disequilibrium (LD) in apples means millions of SNPs may be required for well-powered GWAS. However, rapid LD decay also promises to enable extremely high resolution mapping of causal variants, which holds great potential for advancing MAS.
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26
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Burgarella C, Chantret N, Gay L, Prosperi J, Bonhomme M, Tiffin P, Young ND, Ronfort J. Adaptation to climate through flowering phenology: a case study in
Medicago truncatula. Mol Ecol 2016; 25:3397-415. [DOI: 10.1111/mec.13683] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Concetta Burgarella
- UMR 232 DIADE/DYNADIV Institut de Recherche pour le Developpement (IRD) 911 avenue Agropolis BP 64501, 34394 Montpellier France
- UMR AGAP, Equipe Génomique évolutive et gestion des populations Institut national de Recherche Agronomique (INRA) 34060 Montpellier France
| | - Nathalie Chantret
- UMR AGAP, Equipe Génomique évolutive et gestion des populations Institut national de Recherche Agronomique (INRA) 34060 Montpellier France
| | - Laurène Gay
- UMR AGAP, Equipe Génomique évolutive et gestion des populations Institut national de Recherche Agronomique (INRA) 34060 Montpellier France
| | - Jean‐Marie Prosperi
- UMR AGAP, Equipe Génomique évolutive et gestion des populations Institut national de Recherche Agronomique (INRA) 34060 Montpellier France
| | - Maxime Bonhomme
- UPS Laboratoire de Recherche en Sciences Végétales Université de Toulouse BP42617, Auzeville F‐31326 Castanet‐Tolosan France
- Laboratoire de Recherche en Sciences Végétales CNRS BP42617, Auzeville F‐31326 Castanet‐Tolosan France
| | - Peter Tiffin
- Department of Plant Biology University of Minnesota St. Paul MN 55108 USA
| | - Nevin D. Young
- Department of Plant Biology University of Minnesota St. Paul MN 55108 USA
- Department of Plant Pathology University of Minnesota St. Paul MN 55108 USA
| | - Joelle Ronfort
- UMR AGAP, Equipe Génomique évolutive et gestion des populations Institut national de Recherche Agronomique (INRA) 34060 Montpellier France
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Yule KM, Koop JAH, Alexandre NM, Johnston LR, Whiteman NK. Population structure of a vector-borne plant parasite. Mol Ecol 2016; 25:3332-43. [PMID: 27154249 DOI: 10.1111/mec.13693] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/13/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022]
Abstract
Parasites are among the most diverse groups of life on Earth, yet complex natural histories often preclude studies of their speciation processes. The biology of parasitic plants facilitates in situ collection of data on both genetic structure and the mechanisms responsible for that structure. Here, we studied the role of mating, dispersal and establishment in host race formation of a parasitic plant. We investigated the population genetics of a vector-borne desert mistletoe (Phoradendron californicum) across two legume host tree species (Senegalia greggii and Prosopis velutina) in the Sonoran desert using microsatellites. Consistent with host race formation, we found strong host-associated genetic structure in sympatry, little genetic variation due to geographic site and weak isolation by distance. We hypothesize that genetic differentiation results from differences in the timing of mistletoe flowering by host species, as we found initial flowering date of individual mistletoes correlated with genetic ancestry. Hybrids with intermediate ancestry were detected genetically. Individuals likely resulting from recent, successful establishment events following dispersal between the host species were detected at frequencies similar to hybrids between host races. Therefore, barriers to gene flow between the host races may have been stronger at mating than at dispersal. We also found higher inbreeding and within-host individual relatedness values for mistletoes on the more rare and isolated host species (S. greggii). Our study spanned spatial scales to address how interactions with both vectors and hosts influence parasitic plant structure with implications for parasite virulence evolution and speciation.
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Affiliation(s)
- Kelsey M Yule
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Jennifer A H Koop
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Nicolas M Alexandre
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Lauren R Johnston
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Noah K Whiteman
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA.,Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, USA
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Stewart JJ, Adams WW, Cohu CM, Polutchko SK, Lombardi EM, Demmig-Adams B. Differences in light-harvesting, acclimation to growth-light environment, and leaf structural development between Swedish and Italian ecotypes of Arabidopsis thaliana. PLANTA 2015; 242:1277-90. [PMID: 26189001 DOI: 10.1007/s00425-015-2368-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/29/2015] [Indexed: 05/22/2023]
Abstract
Leaf morphological differences have an impact on light distribution within the leaf, photosynthesis, and photoprotection in Arabidopsis thaliana ecotypes from near the limits of this species' latitudinal distribution in Europe. Leaf morphology, photosynthesis, and photoprotection were characterized in two Arabidopsis ecotypes from near the limits of this species' latitudinal distribution in Europe (63°N and 42°N). The Swedish ecotype formed thicker leaves and upregulated photosynthesis more substantially than the Italian ecotype in high-light environments. Conversely, the smaller rosette formed, and lesser aboveground biomass accumulated, by the Swedish versus the Italian ecotype in low growth-light environments is consistent with a lesser shade tolerance of the Swedish ecotype. The response of the thinner leaves of the Italian ecotype to evenly spaced daily periods of higher light against a background of otherwise non-fluctuating low light was to perform the same rate of photosynthesis with less chlorophyll, rather than exhibiting greater rates of photosynthesis. In contrast, the thicker leaves of the Swedish ecotype showed elevated photosynthetic performance in response to daily supplemental higher light periods in a low-light growth environment. These findings suggest significant self-shading in the lower depths of leaves of the Swedish ecotype by the chloroplasts residing in the upper portions of the leaf, resulting in a requirement for higher incident light to trigger photosynthetic upregulation in the lower portions of its thicker leaves. Conversely, photoprotective responses in the Italian ecotype suggest that more excess light penetrated into the lower depths of this ecotype's leaves. It is speculated that light absorption and the degree of utilization of this absorbed light inform cellular signaling networks that orchestrate leaf structural development, which, in turn, affects light distribution and the level of absorbed versus photosynthetically utilized light in a leaf.
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Affiliation(s)
- Jared J Stewart
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - William W Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Christopher M Cohu
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Stephanie K Polutchko
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Elizabeth M Lombardi
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA
| | - Barbara Demmig-Adams
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
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Jokela V, Trevaskis B, Seppänen MM. Genetic variation in the flowering and yield formation of timothy (Phleum pratense L.) accessions after different photoperiod and vernalization treatments. FRONTIERS IN PLANT SCIENCE 2015; 6:465. [PMID: 26175739 PMCID: PMC4485155 DOI: 10.3389/fpls.2015.00465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 06/11/2015] [Indexed: 06/04/2023]
Abstract
Timothy is a perennial forage grass grown commonly in Boreal regions. This study explored the effect of vernalization and photoperiod (PP) on flowering and growth characteristics and how this related to changes in expression of three flowering related genes in accessions from different geographic origin. Large variation was found in accessions in their vernalization and PP responses. In southern accessions vernalization response or requirement was not observed, the heading date remained unchanged, and plants flowered without vernalization. On the contrary, northern types had obligatory requirement for vernalization and long PP, but the tiller elongation did not require vernalization at 16-h PP. Longer vernalization or PP treatments reduced the genotypical differences in flowering. Moreover, the vernalization saturation progressed stepwise from main tiller to lateral tillers, and this process was more synchronized in southern accessions. The expression of PpVRN1 was associated with vernalization while PpVRN3 accumulated at long PP. A crucial role for PpVRN3 in the transition to flowering was supported as in southern accession the transcript accumulated in non-vernalized plants after transfer to 16-h PP, and the apices transformed to generative stage. Differences in vernalization requirements were associated with variation in expression levels of PpVRN1 and PpVRN3, with higher expression levels in southern type. Most divergent transcript accumulation of PpMADS10 was found under different vernalization conditions. These differences between accessions can be translated into agronomic traits, such as the tiller composition of canopy, which affects the forage yield. The southern types, with minimal vernalization response, have fast re-growth ability and rapidly decreasing nutritive value, whereas northern types grow slowly and have better quality. This information can be utilized in breeding for new cultivars for longer growing seasons at high latitudes.
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Affiliation(s)
- Venla Jokela
- Department of Agricultural Sciences, University of Helsinki, HelsinkiFinland
| | - Ben Trevaskis
- Agriculture Flagship, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACTAustralia
| | - Mervi M. Seppänen
- Department of Agricultural Sciences, University of Helsinki, HelsinkiFinland
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Heterosis and outbreeding depression in crosses between natural populations of Arabidopsis thaliana. Heredity (Edinb) 2015; 115:73-82. [PMID: 26059971 DOI: 10.1038/hdy.2015.18] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 02/09/2015] [Accepted: 02/18/2015] [Indexed: 02/03/2023] Open
Abstract
Understanding the causes and architecture of genetic differentiation between natural populations is of central importance in evolutionary biology. Crosses between natural populations can result in heterosis if recessive or nearly recessive deleterious mutations have become fixed within populations because of genetic drift. Divergence between populations can also result in outbreeding depression because of genetic incompatibilities. The net fitness consequences of between-population crosses will be a balance between heterosis and outbreeding depression. We estimated the magnitude of heterosis and outbreeding depression in the highly selfing model plant Arabidopsis thaliana, by crossing replicate line pairs from two sets of natural populations (C↔R, B↔S) separated by similar geographic distances (Italy↔Sweden). We examined the contribution of different modes of gene action to overall differences in estimates of lifetime fitness and fitness components using joint scaling tests with parental, reciprocal F1 and F2, and backcross lines. One of these population pairs (C↔R) was previously demonstrated to be locally adapted, but locally maladaptive quantitative trait loci were also found, suggesting a role for genetic drift in shaping adaptive variation. We found markedly different genetic architectures for fitness and fitness components in the two sets of populations. In one (C↔R), there were consistently positive effects of dominance, indicating the masking of recessive or nearly recessive deleterious mutations that had become fixed by genetic drift. The other set (B↔S) exhibited outbreeding depression because of negative dominance effects. Additional studies are needed to explore the molecular genetic basis of heterosis and outbreeding depression, and how their magnitudes vary across environments.
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Jensen LM, Jepsen HSK, Halkier BA, Kliebenstein DJ, Burow M. Natural variation in cross-talk between glucosinolates and onset of flowering in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2015; 6:697. [PMID: 26442014 PMCID: PMC4561820 DOI: 10.3389/fpls.2015.00697] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/21/2015] [Indexed: 05/02/2023]
Abstract
Naturally variable regulatory networks control different biological processes including reproduction and defense. This variation within regulatory networks enables plants to optimize defense and reproduction in different environments. In this study we investigate the ability of two enzyme-encoding genes in the glucosinolate pathway, AOP2 and AOP3, to affect glucosinolate accumulation and flowering time. We have introduced the two highly similar enzymes into two different AOP (null) accessions, Col-0 and Cph-0, and found that the genes differ in their ability to affect glucosinolate levels and flowering time across the accessions. This indicated that the different glucosinolates produced by AOP2 and AOP3 serve specific regulatory roles in controlling these phenotypes. While the changes in glucosinolate levels were similar in both accessions, the effect on flowering time was dependent on the genetic background pointing to natural variation in cross-talk between defense chemistry and onset of flowering. This variation likely reflects an adaptation to survival in different environments.
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Affiliation(s)
- Lea M. Jensen
- Department of Plant and Environmental Sciences, Faculty of Science, DNRF Center DynaMo, University of CopenhagenFrederiksberg, Denmark
- Department of Plant and Environmental Sciences, Faculty of Science, Copenhagen Plant Science Centre, University of CopenhagenFrederiksberg, Denmark
| | - Henriette S. K. Jepsen
- Department of Plant and Environmental Sciences, Faculty of Science, DNRF Center DynaMo, University of CopenhagenFrederiksberg, Denmark
- Department of Plant and Environmental Sciences, Faculty of Science, Copenhagen Plant Science Centre, University of CopenhagenFrederiksberg, Denmark
| | - Barbara A. Halkier
- Department of Plant and Environmental Sciences, Faculty of Science, DNRF Center DynaMo, University of CopenhagenFrederiksberg, Denmark
- Department of Plant and Environmental Sciences, Faculty of Science, Copenhagen Plant Science Centre, University of CopenhagenFrederiksberg, Denmark
| | - Daniel J. Kliebenstein
- Department of Plant and Environmental Sciences, Faculty of Science, DNRF Center DynaMo, University of CopenhagenFrederiksberg, Denmark
- Department of Plant Sciences, University of California, DavisDavis, CA, USA
| | - Meike Burow
- Department of Plant and Environmental Sciences, Faculty of Science, DNRF Center DynaMo, University of CopenhagenFrederiksberg, Denmark
- Department of Plant and Environmental Sciences, Faculty of Science, Copenhagen Plant Science Centre, University of CopenhagenFrederiksberg, Denmark
- *Correspondence: Meike Burow, Department of Plant and Environmental Sciences, DNRF Center DynaMo, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
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Levy RC, Kozak GM, Wadsworth CB, Coates BS, Dopman EB. Explaining the sawtooth: latitudinal periodicity in a circadian gene correlates with shifts in generation number. J Evol Biol 2014; 28:40-53. [DOI: 10.1111/jeb.12562] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/21/2014] [Accepted: 11/24/2014] [Indexed: 01/03/2023]
Affiliation(s)
- R. C. Levy
- Department of Biology; Tufts University; Medford MA USA
| | - G. M. Kozak
- Department of Biology; Tufts University; Medford MA USA
| | | | - B. S. Coates
- USDA-ARS; Corn Insects and Crop Genetics Research Unit; Genetics Laboratory; Iowa State University; Ames IA USA
| | - E. B. Dopman
- Department of Biology; Tufts University; Medford MA USA
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Kenney AM, McKay JK, Richards JH, Juenger TE. Direct and indirect selection on flowering time, water-use efficiency (WUE, δ (13)C), and WUE plasticity to drought in Arabidopsis thaliana. Ecol Evol 2014; 4:4505-21. [PMID: 25512847 PMCID: PMC4264900 DOI: 10.1002/ece3.1270] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 07/15/2014] [Accepted: 08/19/2014] [Indexed: 11/09/2022] Open
Abstract
Flowering time and water-use efficiency (WUE) are two ecological traits that are important for plant drought response. To understand the evolutionary significance of natural genetic variation in flowering time, WUE, and WUE plasticity to drought in Arabidopsis thaliana, we addressed the following questions: (1) How are ecophysiological traits genetically correlated within and between different soil moisture environments? (2) Does terminal drought select for early flowering and drought escape? (3) Is WUE plasticity to drought adaptive and/or costly? We measured a suite of ecophysiological and reproductive traits on 234 spring flowering accessions of A. thaliana grown in well-watered and season-ending soil drying treatments, and quantified patterns of genetic variation, correlation, and selection within each treatment. WUE and flowering time were consistently positively genetically correlated. WUE was correlated with WUE plasticity, but the direction changed between treatments. Selection generally favored early flowering and low WUE, with drought favoring earlier flowering significantly more than well-watered conditions. Selection for lower WUE was marginally stronger under drought. There were no net fitness costs of WUE plasticity. WUE plasticity (per se) was globally neutral, but locally favored under drought. Strong genetic correlation between WUE and flowering time may facilitate the evolution of drought escape, or constrain independent evolution of these traits. Terminal drought favored drought escape in these spring flowering accessions of A. thaliana. WUE plasticity may be favored over completely fixed development in environments with periodic drought.
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Affiliation(s)
- Amanda M Kenney
- Department of Biological Sciences, St. Edward's University Austin, Texas
| | - John K McKay
- Department of Bioagricultural Sciences and Pest Management, Colorado State University Fort Collins, Colorado
| | - James H Richards
- Land, Air and Water Resources, University of California, Davis Davis, California
| | - Thomas E Juenger
- Department of Integrative Biology, The University of Texas at Austin Austin, Texas
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Siwinska J, Kadzinski L, Banasiuk R, Gwizdek-Wisniewska A, Olry A, Banecki B, Lojkowska E, Ihnatowicz A. Identification of QTLs affecting scopolin and scopoletin biosynthesis in Arabidopsis thaliana. BMC PLANT BIOLOGY 2014; 14:280. [PMID: 25326030 PMCID: PMC4252993 DOI: 10.1186/s12870-014-0280-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 10/09/2014] [Indexed: 05/08/2023]
Abstract
BACKGROUND Scopoletin and its glucoside scopolin are important secondary metabolites synthesized in plants as a defense mechanism against various environmental stresses. They belong to coumarins, a class of phytochemicals with significant biological activities that is widely used in medical application and cosmetics industry. Although numerous studies showed that a variety of coumarins occurs naturally in several plant species, the details of coumarins biosynthesis and its regulation is not well understood. It was shown previously that coumarins (predominantly scopolin and scopoletin) occur in Arabidopsis thaliana (Arabidopsis) roots, but until now nothing is known about natural variation of their accumulation in this model plant. Therefore, the genetic architecture of coumarins biosynthesis in Arabidopsis has not been studied before. RESULTS Here, the variation in scopolin and scopoletin content was assessed by comparing seven Arabidopsis accessions. Subsequently, a quantitative trait locus (QTL) mapping was performed with an Advanced Intercross Recombinant Inbred Lines (AI-RILs) mapping population EstC (Est-1 × Col). In order to reveal the genetic basis of both scopolin and scopoletin biosynthesis, two sets of methanol extracts were made from Arabidopsis roots and one set was additionally subjected to enzymatic hydrolysis prior to quantification done by high-performance liquid chromatography (HPLC). We identified one QTL for scopolin and five QTLs for scopoletin accumulation. The identified QTLs explained 13.86% and 37.60% of the observed phenotypic variation in scopolin and scopoletin content, respectively. In silico analysis of genes located in the associated QTL intervals identified a number of possible candidate genes involved in coumarins biosynthesis. CONCLUSIONS Together, our results demonstrate for the first time that Arabidopsis is an excellent model for studying the genetic and molecular basis of natural variation in coumarins biosynthesis in plants. It additionally provides a basis for fine mapping and cloning of the genes involved in scopolin and scopoletin biosynthesis. Importantly, we have identified new loci for this biosynthetic process.
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Affiliation(s)
- Joanna Siwinska
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Leszek Kadzinski
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Rafal Banasiuk
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Anna Gwizdek-Wisniewska
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Alexandre Olry
- />Université de Lorraine, UMR 1121 Laboratoire Agronomie et Environnement Nancy-Colmar, 2 avenue de la forêt de Haye, Vandœuvre-lès-Nancy, 54505 France
- />INRA, UMR 1121 Laboratoire Agronomie et Environnement Nancy-Colmar, 2 avenue de la forêt de Haye, Vandœuvre-lès-Nancy, 54505 France
| | - Bogdan Banecki
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Ewa Lojkowska
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
| | - Anna Ihnatowicz
- />Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, ul. Kladki 24, Gdansk, 80-822 Poland
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Mamidi S, Lee RK, Goos JR, McClean PE. Genome-wide association studies identifies seven major regions responsible for iron deficiency chlorosis in soybean (Glycine max). PLoS One 2014; 9:e107469. [PMID: 25225893 PMCID: PMC4166409 DOI: 10.1371/journal.pone.0107469] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/14/2014] [Indexed: 01/08/2023] Open
Abstract
Iron deficiency chlorosis (IDC) is a yield limiting problem in soybean (Glycine max (L.) Merr) production regions with calcareous soils. Genome-wide association study (GWAS) was performed using a high density SNP map to discover significant markers, QTL and candidate genes associated with IDC trait variation. A stepwise regression model included eight markers after considering LD between markers, and identified seven major effect QTL on seven chromosomes. Twelve candidate genes known to be associated with iron metabolism mapped near these QTL supporting the polygenic nature of IDC. A non-synonymous substitution with the highest significance in a major QTL region suggests soybean orthologs of FRE1 on Gm03 is a major gene responsible for trait variation. NAS3, a gene that encodes the enzyme nicotianamine synthase which synthesizes the iron chelator nicotianamine also maps to the same QTL region. Disease resistant genes also map to the major QTL, supporting the hypothesis that pathogens compete with the plant for Fe and increase iron deficiency. The markers and the allelic combinations identified here can be further used for marker assisted selection.
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Affiliation(s)
- Sujan Mamidi
- Genomics and Bioinformatics Program, North Dakota State University, Fargo, North Dakota, United States of America
- Department of Plant Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Rian K. Lee
- Genomics and Bioinformatics Program, North Dakota State University, Fargo, North Dakota, United States of America
- Department of Plant Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Jay R. Goos
- Department of Soil Science, North Dakota State University, Fargo, North Dakota, United States of America
| | - Phillip E. McClean
- Genomics and Bioinformatics Program, North Dakota State University, Fargo, North Dakota, United States of America
- Department of Plant Sciences, North Dakota State University, Fargo, North Dakota, United States of America
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Dittmar EL, Oakley CG, Ågren J, Schemske DW. Flowering time QTL in natural populations ofArabidopsis thalianaand implications for their adaptive value. Mol Ecol 2014; 23:4291-303. [DOI: 10.1111/mec.12857] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 06/27/2014] [Indexed: 01/31/2023]
Affiliation(s)
- Emily L. Dittmar
- Department of Plant Biology and W. K. Kellogg Biological Station; Michigan State University; East Lansing MI 48824 USA
| | | | - Jon Ågren
- Department of Plant Ecology and Evolution; Evolutionary Biology Centre; Uppsala University; Norbyvägen 18 D SE-752 36 Uppsala Sweden
| | - Douglas W. Schemske
- Department of Plant Biology and W. K. Kellogg Biological Station; Michigan State University; East Lansing MI 48824 USA
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Wilczek AM, Cooper MD, Korves TM, Schmitt J. Lagging adaptation to warming climate in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2014; 111:7906-13. [PMID: 24843140 PMCID: PMC4050579 DOI: 10.1073/pnas.1406314111] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer climates will outperform natives and may provide genetic potential for evolutionary rescue. We tested for lagging adaptation to warming climate using banked seeds of the annual weed Arabidopsis thaliana in common garden experiments in four sites across the species' native European range: Valencia, Spain; Norwich, United Kingdom; Halle, Germany; and Oulu, Finland. Genotypes originating from geographic regions near the planting site had high relative fitness in each site, direct evidence for broad-scale geographic adaptation in this model species. However, genotypes originating in sites historically warmer than the planting site had higher average relative fitness than local genotypes in every site, especially at the northern range limit in Finland. This result suggests that local adaptive optima have shifted rapidly with recent warming across the species' native range. Climatic optima also differed among seasonal germination cohorts within the Norwich site, suggesting that populations occurring where summer germination is common may have greater evolutionary potential to persist under future warming. If adaptational lag has occurred over just a few decades in banked seeds of an annual species, it may be an important consideration for managing longer-lived species, as well as for attempts to conserve threatened populations through ex situ preservation.
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Affiliation(s)
- Amity M Wilczek
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912;Department of Natural Sciences, Deep Springs College, Big Pine, CA 93513
| | - Martha D Cooper
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912
| | - Tonia M Korves
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912;Data Analytics Department, The MITRE Corporation, Bedford, MA 01730-1420; and
| | - Johanna Schmitt
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912;Department of Evolution and Ecology, University of California, Davis, CA 95616
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Zuellig MP, Kenney AM, Sweigart AL. Evolutionary genetics of plant adaptation: insights from new model systems. CURRENT OPINION IN PLANT BIOLOGY 2014; 18:44-50. [PMID: 24561539 PMCID: PMC7659028 DOI: 10.1016/j.pbi.2014.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 01/21/2014] [Accepted: 01/26/2014] [Indexed: 05/18/2023]
Abstract
Flowering time and mating system divergence are two of the most common adaptive transitions in plants. We review recent progress toward understanding the genetic basis of these adaptations in new model plant species. For flowering time, we find that individual crosses often reveal a simple genetic basis, but that the loci involved almost always vary within species and across environments, indicating a more complex genetic basis species-wide. Similarly, the transition to self-fertilization is often genetically complex, but this seems to depend on the amount of standing variation and time since species divergence. Recent population genomic studies also raise doubts about the long-term adaptive potential of self-fertilization, providing evidence that purifying selection is less effective in highly selfing species.
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Affiliation(s)
- Matthew P Zuellig
- University of Georgia, Department of Genetics, Fred C. Davidson Life Sciences Complex, Athens, GA 30602, United States
| | - Amanda M Kenney
- University of Georgia, Department of Genetics, Fred C. Davidson Life Sciences Complex, Athens, GA 30602, United States
| | - Andrea L Sweigart
- University of Georgia, Department of Genetics, Fred C. Davidson Life Sciences Complex, Athens, GA 30602, United States.
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Fishman L, Sweigart AL, Kenney AM, Campbell S. Major quantitative trait loci control divergence in critical photoperiod for flowering between selfing and outcrossing species of monkeyflower (Mimulus). THE NEW PHYTOLOGIST 2014; 201:1498-1507. [PMID: 24304557 DOI: 10.1111/nph.12618] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/29/2013] [Indexed: 05/29/2023]
Abstract
• Divergence in flowering time is a key contributor to reproductive isolation between incipient species, as it enforces habitat specialization and causes assortative mating even in sympatry. Understanding the genetic basis of flowering time divergence illuminates the origins and maintenance of species barriers. • We investigated the genetics of divergence in critical photoperiod for flowering between yellow monkeyflowers Mimulus guttatus (outcrosser, summer flowering) and Mimulus nasutus (selfer, spring flowering). We used quantitative trait locus (QTL) mapping of F2 hybrids and fine-mapping in nearly isogenic lines to characterize the genomic regions underlying a > 2 h critical photoperiod difference between allopatric populations, and then tested whether the same QTLs control flowering time in sympatry. • We identified two major QTLs that almost completely explain M. nasutus's ability to flower in early spring; they are shared by allopatric and sympatric population pairs. The smaller QTL is coincident with one that differentiates ecotypes within M. guttatus, but the larger effect QTL appears unique to M. nasutus. • Unlike floral traits associated with mating system divergence, large interspecific differences in flowering phenology depend on only a few loci. Major critical photoperiod QTLs may be 'speciation genes' and also restrict interspecific gene flow in secondary sympatry.
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Affiliation(s)
- Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Andrea L Sweigart
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Amanda M Kenney
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Samantha Campbell
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
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Wolfe MD, Tonsor SJ. Adaptation to spring heat and drought in northeastern Spanish Arabidopsis thaliana. THE NEW PHYTOLOGIST 2014; 201:323-334. [PMID: 24117851 DOI: 10.1111/nph.12485] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/02/2013] [Indexed: 05/23/2023]
Abstract
The extent to which a species' environmental range reflects adaptive differentiation remains an open question. Environmental gradients can lead to adaptive divergence when differences in stressors among sites along the gradient place conflicting demands on the balance of stress responses. The extent to which this is accomplished through stress tolerance vs stress avoidance is also an open question. We present results from a controlled environment study of 48 lineages of Arabidopsis thaliana collected along a gradient in northeastern Spain across which temperatures increase and precipitation decreases with decreasing elevation. We tested the extent to which clinal adaptive divergence in heat and drought is explained through tolerance and avoidance traits by subjecting plants to a dynamic growth chamber cycle of increasing heat and drought stress analogous to low elevation spring in northeastern Spain. Lineages collected at low elevation were the most fit and fitness scaled with elevation of origin. Higher fitness was associated with earlier bolting, greater early allocation to increased numbers of inflorescences, reduction in rosette leaf photosynthesis and earlier fruit ripening. We propose that this is a syndrome of avoidance through early flowering accompanied by restructuring of the organism that adapts A. thaliana to low-elevation Mediterranean climates.
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Affiliation(s)
- Marnin D Wolfe
- Department of Biological Sciences, University of Pittsburgh, 162 Crawford Hall, 4249 Fifth Avenue, Pittsburgh, PA, 15260, USA
| | - Stephen J Tonsor
- Department of Biological Sciences, University of Pittsburgh, 162 Crawford Hall, 4249 Fifth Avenue, Pittsburgh, PA, 15260, USA
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Genetic mapping of adaptation reveals fitness tradeoffs in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2013; 110:21077-82. [PMID: 24324156 DOI: 10.1073/pnas.1316773110] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Organisms inhabiting different environments are often locally adapted, and yet despite a considerable body of theory, the genetic basis of local adaptation is poorly understood. Unanswered questions include the number and effect sizes of adaptive loci, whether locally favored loci reduce fitness elsewhere (i.e., fitness tradeoffs), and whether a lack of genetic variation limits adaptation. To address these questions, we mapped quantitative trait loci (QTL) for total fitness in 398 recombinant inbred lines derived from a cross between locally adapted populations of the highly selfing plant Arabidopsis thaliana from Sweden and Italy and grown for 3 consecutive years at the parental sites (>40,000 plants monitored). We show that local adaptation is controlled by relatively few genomic regions of small to modest effect. A third of the 15 fitness QTL we detected showed evidence of tradeoffs, which contrasts with the minimal evidence for fitness tradeoffs found in previous studies. This difference may reflect the power of our multiyear study to distinguish conditionally neutral QTL from those that reflect fitness tradeoffs. In Sweden, but not in Italy, the local genotype underlying fitness QTL was often maladaptive, suggesting that adaptation there is constrained by a lack of adaptive genetic variation, attributable perhaps to genetic bottlenecks during postglacial colonization of Scandinavia or to recent changes in selection regime caused by climate change. Our results suggest that adaptation to markedly different environments can be achieved through changes in relatively few genomic regions, that fitness tradeoffs are common, and that lack of genetic variation can limit adaptation.
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