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Wang Y, Severing EI, Koornneef M, Aarts MGM. FLC and SVP Are Key Regulators of Flowering Time in the Biennial/Perennial Species Noccaea caerulescens. FRONTIERS IN PLANT SCIENCE 2020; 11:582577. [PMID: 33262778 PMCID: PMC7686048 DOI: 10.3389/fpls.2020.582577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 10/19/2020] [Indexed: 05/25/2023]
Abstract
The appropriate timing of flowering is crucial for plant reproductive success. Studies of the molecular mechanism of flower induction in the model plant Arabidopsis thaliana showed long days and vernalization as major environmental promotive factors. Noccaea caerulescens has an obligate vernalization requirement that has not been studied at the molecular genetics level. Here, we characterize the vernalization requirement and response of four geographically diverse biennial/perennial N. caerulescens accessions: Ganges (GA), Lellingen (LE), La Calamine (LC), and St. Felix de Pallières (SF). Differences in vernalization responsiveness among accessions suggest that natural variation for this trait exists within N. caerulescens. Mutants which fully abolish the vernalization requirement were identified and were shown to contain mutations in the FLOWERING LOCUS C (NcFLC) and SHORT VEGETATIVE PHASE (NcSVP) genes, two key floral repressors in this species. At high temperatures, the non-vernalization requiring flc-1 mutant reverts from flowering to vegetative growth, which is accompanied with a reduced expression of LFY and AP1. This suggested there is "crosstalk" between vernalization and ambient temperature, which might be a strategy to cope with fluctuations in temperature or adopt a more perennial flowering attitude and thus facilitate a flexible evolutionary response to the changing environment across the species range.
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Affiliation(s)
- Yanli Wang
- State Key Laboratory of Protection and Utilization of Subtropical Agriculture Resource, College of Life Sciences, South China Agricultural University, Guangzhou, China
- Laboratory of Genetics, Wageningen University and Research, Wageningen, Netherlands
| | - Edouard I. Severing
- Laboratory of Genetics, Wageningen University and Research, Wageningen, Netherlands
| | - Maarten Koornneef
- Laboratory of Genetics, Wageningen University and Research, Wageningen, Netherlands
| | - Mark G. M. Aarts
- Laboratory of Genetics, Wageningen University and Research, Wageningen, Netherlands
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2
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McGinn M, Phippen WB, Chopra R, Bansal S, Jarvis BA, Phippen ME, Dorn KM, Esfahanian M, Nazarenus TJ, Cahoon EB, Durrett TP, Marks MD, Sedbrook JC. Molecular tools enabling pennycress (Thlaspi arvense) as a model plant and oilseed cash cover crop. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:776-788. [PMID: 30230695 PMCID: PMC6419581 DOI: 10.1111/pbi.13014] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/25/2018] [Accepted: 09/04/2018] [Indexed: 05/05/2023]
Abstract
Thlapsi arvense L. (pennycress) is being developed as a profitable oilseed cover crop for the winter fallow period throughout the temperate regions of the world, controlling soil erosion and nutrients run-off on otherwise barren farmland. We demonstrate that pennycress can serve as a user-friendly model system akin to Arabidopsis that is well-suited for both laboratory and field experimentation. We sequenced the diploid genome of the spring-type Spring 32-10 inbred line (1C DNA content of 539 Mb; 2n = 14), identifying variation that may explain phenotypic differences with winter-type pennycress, as well as predominantly a one-to-one correspondence with Arabidopsis genes, which makes translational research straightforward. We developed an Agrobacterium-mediated floral dip transformation method (0.5% transformation efficiency) and introduced CRISPR-Cas9 constructs to produce indel mutations in the putative FATTY ACID ELONGATION1 (FAE1) gene, thereby abolishing erucic acid production and creating an edible seed oil comparable to that of canola. We also stably transformed pennycress with the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene, producing low-viscosity acetyl-triacylglycerol-containing seed oil suitable as a diesel-engine drop-in fuel. Adoption of pennycress as a model system will accelerate oilseed-crop translational research and facilitate pennycress' rapid domestication to meet the growing sustainable food and fuel demands.
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Affiliation(s)
- Michaela McGinn
- School of Biological SciencesIllinois State UniversityNormalILUSA
| | | | - Ratan Chopra
- Department of Plant BiologyUniversity of MinnesotaSaint PaulMNUSA
| | - Sunil Bansal
- Department of Biochemistry and Molecular BiophysicsKansas State UniversityManhattanKSUSA
| | - Brice A. Jarvis
- School of Biological SciencesIllinois State UniversityNormalILUSA
| | | | - Kevin M. Dorn
- Department of Plant BiologyUniversity of MinnesotaSaint PaulMNUSA
| | | | - Tara J. Nazarenus
- Center for Plant Science Innovation and Department of BiochemistryUniversity of Nebraska‐LincolnLincolnNEUSA
| | - Edgar B. Cahoon
- Center for Plant Science Innovation and Department of BiochemistryUniversity of Nebraska‐LincolnLincolnNEUSA
| | - Timothy P. Durrett
- Department of Biochemistry and Molecular BiophysicsKansas State UniversityManhattanKSUSA
| | - M. David Marks
- Department of Plant BiologyUniversity of MinnesotaSaint PaulMNUSA
| | - John C. Sedbrook
- School of Biological SciencesIllinois State UniversityNormalILUSA
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3
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Nibau C, Gallemí M, Dadarou D, Doonan JH, Cavallari N. Thermo-Sensitive Alternative Splicing of FLOWERING LOCUS M Is Modulated by Cyclin-Dependent Kinase G2. FRONTIERS IN PLANT SCIENCE 2019; 10:1680. [PMID: 32038671 PMCID: PMC6987439 DOI: 10.3389/fpls.2019.01680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/29/2019] [Indexed: 05/05/2023]
Abstract
The ability to sense environmental temperature and to coordinate growth and development accordingly, is critical to the reproductive success of plants. Flowering time is regulated at the level of gene expression by a complex network of factors that integrate environmental and developmental cues. One of the main players, involved in modulating flowering time in response to changes in ambient temperature is FLOWERING LOCUS M (FLM). FLM transcripts can undergo extensive alternative splicing producing multiple variants, of which FLM-β and FLM-δ are the most representative. While FLM-β codes for the flowering repressor FLM protein, translation of FLM-δ has the opposite effect on flowering. Here we show that the cyclin-dependent kinase G2 (CDKG2), together with its cognate cyclin, CYCLYN L1 (CYCL1) affects the alternative splicing of FLM, balancing the levels of FLM-β and FLM-δ across the ambient temperature range. In the absence of the CDKG2/CYCL1 complex, FLM-β expression is reduced while FLM-δ is increased in a temperature dependent manner and these changes are associated with an early flowering phenotype in the cdkg2 mutant lines. In addition, we found that transcript variants retaining the full FLM intron 1 are sequestered in the cell nucleus. Strikingly, FLM intron 1 splicing is also regulated by CDKG2/CYCL1. Our results provide evidence that temperature and CDKs regulate the alternative splicing of FLM, contributing to flowering time definition.
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Affiliation(s)
- Candida Nibau
- Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
- *Correspondence: Nicola Cavallari, ; Candida Nibau,
| | - Marçal Gallemí
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Despoina Dadarou
- Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - John H. Doonan
- Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Nicola Cavallari
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Max F. Perutz Laboratories, Medical University of Vienna, Vienna, Austria
- *Correspondence: Nicola Cavallari, ; Candida Nibau,
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4
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Shen W, Yao X, Ye T, Ma S, Liu X, Yin X, Wu Y. Arabidopsis Aspartic Protease ASPG1 Affects Seed Dormancy, Seed Longevity and Seed Germination. PLANT & CELL PHYSIOLOGY 2018; 59:1415-1431. [PMID: 29648652 DOI: 10.1093/pcp/pcy070] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 04/02/2018] [Indexed: 06/08/2023]
Abstract
Seed storage proteins (SSPs) provide free amino acids and energy for the process of seed germination. Although degradation of SSPs by the aspartic proteases isolated from seeds has been documented in vitro, there is still no genetic evidence for involvement of aspartic proteases in seed germination. Here we report that the aspartic protease ASPG1 (ASPARTIC PROTEASE IN GUARD CELL 1) plays an important role in the process of dormancy, viability and germination of Arabidopsis seeds. We show that aspg1-1 mutants have enhanced seed dormancy and reduced seed viability. A significant increase in expression of DELLA genes which act as repressors in the gibberellic acid signal transduction pathway were detected in aspg1-1 during seed germination. Seed germination of aspg1-1 mutants was more sensitive to treatment with paclobutrazol (PAC; a gibberellic acid biosynthesis inhibitor). In contrast, seed germination of ASPG1 overexpression (OE) transgenic lines showed resistant to PAC. The degradation of SSPs in germinating seeds was severely impaired in aspg1-1 mutants. Moreover, the development of aspg1-1 young seedlings was arrested when grown on the nutrient-free medium. Thus ASPG1 is important for seed dormancy, seed longevity and seed germination, and its function is associated with degradation of SSPs and regulation of gibberellic acid signaling in Arabidopsis.
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Affiliation(s)
- Wenzhong Shen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuan Yao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Tiantian Ye
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Sheng Ma
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiong Liu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiaoming Yin
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yan Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
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5
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Edwards B, Burghardt LT, Kovach KE, Donohue K. Canalization of Seasonal Phenology in the Presence of Developmental Variation: Seed Dormancy Cycling in an Annual Weed. Integr Comp Biol 2018; 57:1021-1039. [PMID: 28992196 DOI: 10.1093/icb/icx065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Variation in the developmental timing in one life stage may ramify within and across generations to disrupt optimal phenology of other life stages. By focusing on a common mechanism of developmental arrest in plants-seed dormancy-we investigated how variation in flowering time influenced seed germination behavior and identified potential processes that can lead to canalized germination behavior despite variation in reproductive timing. We quantified effects of reproductive timing on dormancy cycling by experimentally manipulating the temperature during seed maturation and the seasonal timing of seed dispersal/burial, and by assessing temperature-dependent germination of un-earthed seeds over a seasonal cycle. We found that reproductive timing, via both seed-maturation temperature and the timing of dispersal, strongly influenced germination behavior in the weeks immediately following seed burial. However, buried seeds subsequently canalized their germination behavior, after losing primary dormancy and experiencing natural temperature and moisture conditions in the field. After the complete loss of primary dormancy, germination behavior was similar across seed-maturation and dispersal treatments, even when secondary dormancy was induced. Maternal effects themselves may contribute to the canalization of germination: first, by inducing stronger dormancy in autumn-matured seeds, and second by modifying the responses of those seeds to their ambient environment. Genotypes differed in dormancy cycling, with functional alleles of known dormancy genes necessary for the suppression of germination at warm temperatures in autumn through spring across multiple years. Loss of function of dormancy genes abolished almost all dormancy cycling. In summary, effects of reproductive phenology on dormancy cycling of buried seeds were apparent only as long as seeds retained primary dormancy, and a combination of genetically imposed seed dormancy, maternally induced seed dormancy, and secondary dormancy can mitigate variation in germination behavior imposed by variation in reproductive phenology.
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Affiliation(s)
- Brianne Edwards
- Biology Department, Duke University, Box 90338, Durham, NC 27708, USA
| | - Liana T Burghardt
- Biology Department, Duke University, Box 90338, Durham, NC 27708, USA
| | | | - Kathleen Donohue
- Biology Department, Duke University, Box 90338, Durham, NC 27708, USA
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6
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Rubin MJ, Friedman J. The role of cold cues at different life stages on germination and flowering phenology. AMERICAN JOURNAL OF BOTANY 2018; 105:749-759. [PMID: 29683478 DOI: 10.1002/ajb2.1055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY The timing of major phenological transitions is critical to lifetime fitness, and life history theory predicts differences for annual and perennial plants. To correctly time these transitions, many plants rely on environmental cues such as exposure to extended periods of cold, which may occur at different stages throughout their lifetime. METHODS We studied the role of cold at different life stages, by jointly exposing seed (stratification) and rosettes (vernalization) to cold. We used 23 populations of Mimulus guttatus, which vary from annuals to perennials, and investigated how cold at one or both stages affected germination, flowering, growth, and biomass. KEY RESULTS We found that stratification and vernalization interact to affect life cycle transitions, and that cold at either stage could synchronize flowering phenology. For perennials, either stratification or vernalization is necessary for maximum flowering. We also found that germination timing covaried with later traits. Moreover, plants from environments with dissimilar climates displayed different phenological responses to stratification or vernalization. CONCLUSIONS In general, cold is more important for seed germination in annuals and plants from environments with warm temperatures and variable precipitation. In contrast, cold is more important for flowering in perennials: it accelerates flowering in plants from lower precipitation environments, and it increases flowering proportion in plants from cooler, more stable precipitation environments. We discuss our findings in the context of the variable environments plants experience within a population and the variation encountered across the biogeographic native range of the species.
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Affiliation(s)
- Matthew J Rubin
- Department of Biology, Syracuse University, 110 College Place, Syracuse, NY, 13244, USA
| | - Jannice Friedman
- Department of Biology, Syracuse University, 110 College Place, Syracuse, NY, 13244, USA
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7
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Salmela MJ, McMinn RL, Guadagno CR, Ewers BE, Weinig C. Circadian Rhythms and Reproductive Phenology Covary in a Natural Plant Population. J Biol Rhythms 2018; 33:245-254. [DOI: 10.1177/0748730418764525] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
| | - Robby L. McMinn
- Department of Botany, University of Wyoming, Laramie, Wyoming
- Program in Ecology, University of Wyoming, Laramie, Wyoming
| | | | - Brent E. Ewers
- Department of Botany, University of Wyoming, Laramie, Wyoming
- Program in Ecology, University of Wyoming, Laramie, Wyoming
| | - Cynthia Weinig
- Department of Botany, University of Wyoming, Laramie, Wyoming
- Program in Ecology, University of Wyoming, Laramie, Wyoming
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
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8
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Płażek A, Dubert F, Kopeć P, Dziurka M, Kalandyk A, Pastuszak J, Wolko B. Seed Hydropriming and Smoke Water Significantly Improve Low-Temperature Germination of Lupinus angustifolius L. Int J Mol Sci 2018; 19:E992. [PMID: 29587459 PMCID: PMC5979301 DOI: 10.3390/ijms19040992] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/23/2018] [Accepted: 03/23/2018] [Indexed: 12/01/2022] Open
Abstract
Seed imbibition under cold temperature is dangerous when dry seeds have relatively low water content. The aim of this study was to investigate germination of 20 lines/cultivars of narrow-leaf lupine at 7 °C (cold) and 13 °C (control) under the influence of smoke water and following seed hydropriming for 3 h at 20 °C. The efficacy of individual treatments was examined with regard to seed protection during low-temperature germination. Based on seed germination, vigour at cold was evaluated four days after sowing by means of hypocotyl length, the studied lines/cultivars were divided into three groups with low, high and very high germination rates. Germination vigour correlated with cell membrane permeability, dehydrogenase activity and abscisic acid (ABA) content and was analysed in the seeds one day after sowing. Gibberellin content did not correlate with germination vigour. The seeds of weakly germinating lines/cultivars had the highest cell permeability and ABA content as well as the lowest amylolytic activity at both studied temperatures. Additionally, the vigour of weakly germinating seeds at 7 °C correlated with dehydrogenase activity. Three-hour hydropriming was the most effective for seed germination under cold due to reduced cell membrane permeability and ABA level. Stimulating effects of smoke water on germination under cold could be explained by enhanced dehydrogenase activity.
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Affiliation(s)
- Agnieszka Płażek
- Department of Plant Physiology, University of Agriculture, Podłużna 3, 30-239 Kraków, Poland.
| | - Franciszek Dubert
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Przemysław Kopeć
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Michał Dziurka
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Agnieszka Kalandyk
- Polish Academy of Sciences, Institute of Plant Physiology, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Jakub Pastuszak
- Department of Plant Physiology, University of Agriculture, Podłużna 3, 30-239 Kraków, Poland.
| | - Bogdan Wolko
- Polish Academy of Sciences, Institute of Plant Genetics, Strzeszyńska 34, 60-479 Poznań, Poland.
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9
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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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10
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Taylor JL, Massiah A, Kennedy S, Hong Y, Jackson SD. FLC expression is down-regulated by cold treatment in Diplotaxis tenuifolia (wild rocket), but flowering time is unaffected. JOURNAL OF PLANT PHYSIOLOGY 2017; 214:7-15. [PMID: 28419907 PMCID: PMC5477103 DOI: 10.1016/j.jplph.2017.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/22/2017] [Accepted: 03/24/2017] [Indexed: 05/07/2023]
Abstract
Wild rocket (Diplotaxis tenuifolia) has become a very popular salad leaf due to its peppery taste. It is part of the Brassicaceae family and thus has a high level of homology at the DNA level to other Brassica species including Arabidopsis thaliana. The vernalization and photoperiodic requirements of wild rocket have not been reported to date. Photoperiodic experiments described here demonstrate that rocket is a facultative long day plant. To investigate the vernalization requirement, both seed and young plants were given vernalization treatments at 4°C for different lengths of time. A rocket homologue of FLOWERING LOCUS C (DtFLC) was isolated and shown to functionally complement the Arabidopsis FRI+flc3 null mutant. Whilst the expression of DtFLC was significantly reduced after just one week of cold treatment, cold treatments of two to eight weeks had no significant effect on bolting time of wild rocket indicating that rocket does not have a vernalization requirement. These findings illustrate that important fundamental differences can exist between model and crop plant species, such as in this case where down-regulation of DtFLC expression does not enable earlier flowering in wild rocket as it does in Arabidopsis and many other Brassica species.
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Affiliation(s)
- Jemma L Taylor
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Andrea Massiah
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Sue Kennedy
- Elsoms Seeds Ltd, Pinchbeck Road, Spalding PE11 1QG, UK
| | - Yiguo Hong
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Stephen D Jackson
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.
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11
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Blair L, Auge G, Donohue K. Effect of FLOWERING LOCUS C on seed germination depends on dormancy. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:493-506. [PMID: 32480582 DOI: 10.1071/fp16368] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/28/2016] [Indexed: 05/11/2023]
Abstract
FLOWERING LOCUS C (FLC) has a major regulatory role in the timing of flowering in Arabidopsis thaliana (L.) Heynh. and has more recently been shown to influence germination. Here, we investigated the conditions under which FLC influences germination, and demonstrated that its effect depends on the level of primary and secondary dormancy and the temperature of seed imbibition. We tested the germination response of genotypes with different degrees of FLC activity over the course of after-ripening and after secondary dormancy induction by hot stratification. Genotypes with high FLC-activity showed higher germination; this response was greatest when seeds exhibited primary dormancy or were induced into secondary dormancy by hot stratification. In this study, which used less dormant seeds, the effect of FLC was more evident at 22°C, the less permissive germination temperature, than at 10°C, in contrast to prior published results that used more dormant seeds. Thus, because effects of FLC variation depend on dormancy, and because the range of temperature that permits germination also depends on dormancy, the temperature at which FLC affects germination can also vary with dormancy. Finally, we document that the effect of FLC can depend on FRIGIDA and that FRIGIDA itself appears to influence germination. Thus, pleiotropy between germination and flowering pathways in A. thaliana extends beyond FLC and involves other genes in the FLC genetic pathway.
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Affiliation(s)
- Logan Blair
- Duke University, Department of Biology, Box 90338, Durham, NC 27708, USA
| | - Gabriela Auge
- Duke University, Department of Biology, Box 90338, Durham, NC 27708, USA
| | - Kathleen Donohue
- Duke University, Department of Biology, Box 90338, Durham, NC 27708, USA
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12
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Yarur A, Soto E, León G, Almeida AM. The sweet cherry (Prunus avium) FLOWERING LOCUS T gene is expressed during floral bud determination and can promote flowering in a winter-annual Arabidopsis accession. PLANT REPRODUCTION 2016; 29:311-322. [PMID: 27878597 DOI: 10.1007/s00497-016-0296-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/15/2016] [Indexed: 05/18/2023]
Abstract
FT gene is expressed in leaves and buds and is involved in floral meristem determination and bud development in sweet cherry. In woody fruit perennial trees, floral determination, dormancy and bloom, depends on perception of different environmental and endogenous cues which converge to a systemic signaling gene known as FLOWERING LOCUS T (FT). In long-day flowering plants, FT is expressed in the leaves on long days. The protein travels through the phloem to the shoot apical meristem, where it induces flower determination. In perennial plants, meristem determination and flowering are separated by a dormancy period. Meristem determination takes place in summer, but flowering occurs only after a dormancy period and cold accumulation during winter. The roles of FT are not completely clear in meristem determination, dormancy release, and flowering in perennial plants. We cloned FT from sweet cherry (Prunus avium) and analyzed its expression pattern in leaves and floral buds during spring and summer. Phylogenetic analysis shows high identity of the FT cloned sequence with orthologous genes from other Rosaceae species. Our results show that FT is expressed in both leaves and floral buds and increases when the daylight reached 12 h. The peak in FT expression was coincident with floral meristem identity genes expression and morphological changes typical of floral meristem determination. The Edi-0 Arabidopsis ecotype, which requires vernalization to flower, was transformed with a construct for overexpression of PavFT. These transgenic plants showed an early-flowering phenotype without cold treatment. Our results suggest that FT is involved in floral meristem determination and bud development in sweet cherry. Moreover, we show that FT is expressed in both leaves and floral buds in this species, in contrast to annual plants.
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Affiliation(s)
- Antonia Yarur
- Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, República 217, Santiago, Chile
| | - Esteban Soto
- Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, República 217, Santiago, Chile
| | - Gabriel León
- Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, República 217, Santiago, Chile
| | - Andrea Miyasaka Almeida
- Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andrés Bello, República 217, Santiago, Chile.
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13
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Roles AJ, Rutter MT, Dworkin I, Fenster CB, Conner JK. Field measurements of genotype by environment interaction for fitness caused by spontaneous mutations in Arabidopsis thaliana. Evolution 2016; 70:1039-50. [PMID: 27061194 DOI: 10.1111/evo.12913] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 03/24/2016] [Indexed: 12/24/2022]
Abstract
As the ultimate source of genetic diversity, spontaneous mutation is critical to the evolutionary process. The fitness effects of spontaneous mutations are almost always studied under controlled laboratory conditions rather than under the evolutionarily relevant conditions of the field. Of particular interest is the conditionality of new mutations-that is, is a new mutation harmful regardless of the environment in which it is found? In other words, what is the extent of genotype-environment interaction for spontaneous mutations? We studied the fitness effects of 25 generations of accumulated spontaneous mutations in Arabidopsis thaliana in two geographically widely separated field environments, in Michigan and Virginia. At both sites, mean total fitness of mutation accumulation lines exceeded that of the ancestors, contrary to the expected decrease in the mean due to new mutations but in accord with prior work on these MA lines. We observed genotype-environment interactions in the fitness effects of new mutations, such that the effects of mutations in Michigan were a poor predictor of their effects in Virginia and vice versa. In particular, mutational variance for fitness was much larger in Virginia compared to Michigan. This strong genotype-environment interaction would increase the amount of genetic variation maintained by mutation-selection balance.
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Affiliation(s)
- Angela J Roles
- Biology Department, Oberlin College, Oberlin, Ohio, 44074. .,Kellogg Biological Station, Michigan State University, East Lansing, Michigan, 48824. .,Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824.
| | - Matthew T Rutter
- Department of Biology, College of Charleston, Charleston, South Carolina, 29401.,Department of Biology, University of Maryland, College Park, Maryland, 20742
| | - Ian Dworkin
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824.,Department of Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Charles B Fenster
- Department of Biology, University of Maryland, College Park, Maryland, 20742
| | - Jeffrey K Conner
- Kellogg Biological Station, Michigan State University, East Lansing, Michigan, 48824.,Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824
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Li P, Filiault D, Box MS, Kerdaffrec E, van Oosterhout C, Wilczek AM, Schmitt J, McMullan M, Bergelson J, Nordborg M, Dean C. Multiple FLC haplotypes defined by independent cis-regulatory variation underpin life history diversity in Arabidopsis thaliana. Genes Dev 2014; 28:1635-40. [PMID: 25035417 PMCID: PMC4117938 DOI: 10.1101/gad.245993.114] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A key question in evolutionary biology is how molecular variation relates to phenotypic diversity. Arabidopsis FLOWERING LOCUS C (FLC) plays a key role in controlling vernalization—the acceleration of flowering by prolonged cold. Li et al. identify five functionally distinct FLC haplotypes, defined by noncoding sequence variation, which vary in FLC expression level and silencing. Allelic heterogeneity at this single locus accounts for a large proportion of variation in Arabidopsis vernalization. This study advances our understanding of adaptation and provides a new paradigm for analysis of complex traits. Relating molecular variation to phenotypic diversity is a central goal in evolutionary biology. In Arabidopsis thaliana, FLOWERING LOCUS C (FLC) is a major determinant of variation in vernalization—the acceleration of flowering by prolonged cold. Here, through analysis of 1307 A. thaliana accessions, we identify five predominant FLC haplotypes defined by noncoding sequence variation. Genetic and transgenic experiments show that they are functionally distinct, varying in FLC expression level and rate of epigenetic silencing. Allelic heterogeneity at this single locus accounts for a large proportion of natural variation in vernalization that contributes to adaptation of A. thaliana.
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Affiliation(s)
- Peijin Li
- John Innes Centre, Norwich NR4 7UH, United Kingdom;
| | - Daniele Filiault
- Gregor Mendel Institute, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Mathew S Box
- John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Envel Kerdaffrec
- Gregor Mendel Institute, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Cock van Oosterhout
- Department of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | | | - Johanna Schmitt
- University of California at Davis, Davis, California 95616, USA
| | - Mark McMullan
- Department of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Joy Bergelson
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA
| | - Magnus Nordborg
- Gregor Mendel Institute, Austrian Academy of Sciences, 1030 Vienna, Austria
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Lu JJ, Tan DY, Baskin JM, Baskin CC. Germination season and watering regime, but not seed morph, affect life history traits in a cold desert diaspore-heteromorphic annual. PLoS One 2014; 9:e102018. [PMID: 25013967 PMCID: PMC4094427 DOI: 10.1371/journal.pone.0102018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 06/15/2014] [Indexed: 11/18/2022] Open
Abstract
Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or silique and seed production. Seeds in watered plots germinated in autumn (AW) and spring (SW) but only in spring for non-watered plots (SNW). A high percentage of AW, SW and SNW plants survived and reproduced, but flowering date and flowering period of autumn- vs. spring-germinated plants differed. Dry mass also differed with germination season/watering regime (AW > SW > SNW). Number of siliques and seeds increased with plant size (AW > SW > SNW), whereas percent dry mass allocated to reproduction was higher in small plants: SNW > SW > AW. Thus, although seed morph did not affect the expression of life history traits, germination season and watering regime significantly affected phenology, plant size and accumulation and allocation of biomass to reproduction. Flexibility throughout the life cycle of D. strictus is an adaptation to the variation in timing and amount of rainfall in its cold desert habitat.
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Affiliation(s)
- Juan J. Lu
- Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urümqi, China
| | - Dun Y. Tan
- Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urümqi, China
- * E-mail: (DYT); (CCB)
| | - Jerry M. Baskin
- Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urümqi, China
- Department of Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Carol C. Baskin
- Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urümqi, China
- Department of Biology, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail: (DYT); (CCB)
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16
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Des Marais DL, Hernandez KM, Juenger TE. Genotype-by-Environment Interaction and Plasticity: Exploring Genomic Responses of Plants to the Abiotic Environment. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135806] [Citation(s) in RCA: 256] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David L. Des Marais
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712;
| | - Kyle M. Hernandez
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712;
| | - Thomas E. Juenger
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712;
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
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17
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Distelbarth H, Nägele T, Heyer AG. Responses of antioxidant enzymes to cold and high light are not correlated to freezing tolerance in natural accessions of Arabidopsis thaliana. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:982-990. [PMID: 23578291 DOI: 10.1111/j.1438-8677.2012.00718.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/06/2012] [Indexed: 06/02/2023]
Abstract
Low temperatures and high light cause imbalances in primary and secondary reactions of photosynthesis, and thus can result in oxidative stress. Plants employ a range of low-molecular weight antioxidants and antioxidant enzymes to prevent oxidative damage, and antioxidant defence is considered an important component of stress tolerance. To figure out whether oxidative stress and antioxidant defence are key factors defining the different cold acclimation capacities of natural accessions of the model plant Arabidopsis thaliana, we investigated hydrogen peroxide (H2 O2 ) production, antioxidant enzyme activity and lipid peroxidation during a time course of cold treatment and exposure to high light in four differentially cold-tolerant natural accessions of Arabidopsis (C24, Nd, Rsch, Te) that span the European distribution range of the species. All accessions except Rsch (from Russia) had elevated H2 O2 in the cold, indicating that production of reactive oxygen species is part of the cold response in Arabidopsis. Glutathione reductase activity increased in all but Rsch, while ascorbate peroxidase and superoxide dismutase were unchanged and catalase decreased in all but Rsch. Under high light, the Scandinavian accession Te had elevated levels of H2 O2 . Te appeared most sensitive to oxidative stress, having higher malondialdehyde (MDA) levels in the cold and under high light, while only high light caused elevated MDA in the other accessions. Although the most freezing-tolerant, Te had the highest sensitivity to oxidative stress. No correlation was found between freezing tolerance and activity of antioxidant enzymes in the four accessions investigated, arguing against a key role for antioxidant defence in the differential cold acclimation capacities of Arabidopsis accessions.
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Affiliation(s)
- H Distelbarth
- Department of Plant Biotechnology, Institute of Biology, University of Stuttgart, Stuttgart, Germany
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18
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MacMillan CP, O Donnell PJ, Smit AM, Evans R, Stachurski ZH, Torr K, West M, Baltunis J, Strabala TJ. A survey of the natural variation in biomechanical and cell wall properties in inflorescence stems reveals new insights into the utility of Arabidopsis as a wood model. FUNCTIONAL PLANT BIOLOGY : FPB 2013; 40:662-676. [PMID: 32481139 DOI: 10.1071/fp12386] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/24/2013] [Indexed: 06/11/2023]
Abstract
The natural trait variation in Arabidopsis thaliana (L.) Heynh. accessions is an important resource for understanding many biological processes but it is underexploited for wood-related properties. Twelve A. thaliana accessions from diverse geographical locations were examined for variation in secondary growth, biomechanical properties, cell wall glycan content, cellulose microfibril angle (MFA) and flowering time. The effect of daylength was also examined. Secondary growth in rosette and inflorescence stems was observed in all accessions. Organised cellulose microfibrils in inflorescence stems were found in plants grown under long and short days. A substantial range of phenotypic variation was found in biochemical and wood-related biophysical characteristics, particularly for tensile strength, tensile stiffness, MFA and some cell wall components. The four monosaccharides galactose, arabinose, rhamnose and fucose strongly correlated with each other as well as with tensile strength and MFA, consistent with mutations in arabinogalactan protein and fucosyl- and xyloglucan galactosyl-transferase genes that result in decreases in strength. Conversely, these variables showed negative correlations with lignin content. Our data support the notion that large-scale natural variation studies of wood-related biomechanical and biochemical properties of inflorescence stems will be useful for the identification of novel genes important for wood formation and quality, and therefore biomaterial and renewable biofuel production.
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Affiliation(s)
| | | | | | - Rob Evans
- CSIRO Materials Science and Engineering, Melbourne, Vic. 3168, Australia
| | - Zbigniew H Stachurski
- College of Engineering, Australian National University, Canberra, ACT 0200, Australia
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19
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Quilot-Turion B, Leppälä J, Leinonen PH, Waldmann P, Savolainen O, Kuittinen H. Genetic changes in flowering and morphology in response to adaptation to a high-latitude environment in Arabidopsis lyrata. ANNALS OF BOTANY 2013; 111:957-68. [PMID: 23519836 PMCID: PMC3631339 DOI: 10.1093/aob/mct055] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/29/2013] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS The adaptive plastic reactions of plant populations to changing climatic factors, such as winter temperatures and photoperiod, have changed during range shifts after the last glaciation. Timing of flowering is an adaptive trait regulated by environmental cues. Its genetics has been intensively studied in annual plants, but in perennials it is currently not well characterized. This study examined the genetic basis of differentiation in flowering time, morphology, and their plastic responses to vernalization in two locally adapted populations of the perennial Arabidopsis lyrata: (1) to determine whether the two populations differ in their vernalization responses for flowering phenology and morphology; and (2) to determine the genomic areas governing differentiation and vernalization responses. METHODS Two A. lyrata populations, from central Europe and Scandinavia, were grown in growth-chamber conditions with and without cold treatment. A QTL analysis was performed to find genomic regions that interact with vernalization. KEY RESULTS The population from central Europe flowered more rapidly and invested more in inflorescence growth than the population from alpine Scandinavia, especially after vernalization. The alpine population had consistently a low number of inflorescences and few flowers, suggesting strong constraints due to a short growing season, but instead had longer leaves and higher leaf rosettes. QTL mapping in the F2 population revealed genomic regions governing differentiation in flowering time and morphology and, in some cases, the allelic effects from the two populations on a trait were influenced by vernalization (QTL × vernalization interactions). CONCLUSIONS The results indicate that many potentially adaptive genetic changes have occurred during colonization; the two populations have diverged in their plastic responses to vernalization in traits closely connected to fitness through changes in many genomic areas.
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20
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Grillo MA, Li C, Hammond M, Wang L, Schemske DW. Genetic architecture of flowering time differentiation between locally adapted populations of Arabidopsis thaliana. THE NEW PHYTOLOGIST 2013; 197:1321-1331. [PMID: 23311994 DOI: 10.1111/nph.12109] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/15/2012] [Indexed: 05/18/2023]
Abstract
To gain an understanding of the genetic basis of adaptation, we conducted quantitative trait locus (QTL) mapping for flowering time variation between two winter annual populations of Arabidopsis thaliana that are locally adapted and display distinct flowering times. QTL mapping was performed with large (n = 384) F(2) populations with and without vernalization, in order to reveal both the genetic basis of a vernalization requirement and that of variation in flowering time given vernalization. In the nonvernalization treatment, none of the Sweden parents flowered, whereas all of the Italy parents and 42% of the F(2)s flowered. We identified three QTLs for flowering without vernalization, with much of the variation being attributed to a QTL co-localizing with FLOWERING LOCUS C (FLC). In the vernalization treatment, all parents and F(2)s flowered, and six QTLs of small to moderate effect were revealed, with underlying candidate genes that are members of the vernalization pathway. We found no evidence for a role of FRIGIDA in the regulation of flowering times. These results contribute to a growing body of evidence aimed at the identification of ecologically relevant genetic variation for flowering time in Arabidopsis, and set the stage for functional studies to determine the link between flowering time loci and fitness.
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Affiliation(s)
- Michael A Grillo
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Changbao Li
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Mark Hammond
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Lijuan Wang
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Douglas W Schemske
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
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21
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Kemi U, Niittyvuopio A, Toivainen T, Pasanen A, Quilot-Turion B, Holm K, Lagercrantz U, Savolainen O, Kuittinen H. Role of vernalization and of duplicated FLOWERING LOCUS C in the perennial Arabidopsis lyrata. THE NEW PHYTOLOGIST 2013; 197:323-335. [PMID: 23106477 DOI: 10.1111/j.1469-8137.2012.04378.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 09/07/2012] [Indexed: 05/08/2023]
Abstract
FLOWERING LOCUS C (FLC) is one of the main genes influencing the vernalization requirement and natural flowering time variation in the annual Arabidopsis thaliana. Here we studied the effects of vernalization on flowering and its genetic basis in the perennial Arabidopsis lyrata. Two tandemly duplicated FLC genes (FLC1 and FLC2) were compared with respect to expression and DNA sequence. The effect of vernalization on flowering and on the expression of FLC1 was studied in three European populations. The genetic basis of the FLC1 expression difference between two of the populations was further studied by expression quantitative trait locus (eQTL) mapping and sequence analysis. FLC1 was shown to have a likely role in the vernalization requirement for flowering in A. lyrata. Vernalization decreased its expression and the northern study populations showed higher FLC1 expression than the southern one. eQTL mapping between two of the populations revealed one eQTL affecting FLC1 expression in the genomic region containing the FLC genes. Most FLC1 sequence differences between the study populations were found in the promoter region and in the first intron. Variation in the FLC1 sequence may cause differences in FLC1 expression between late- and early-flowering A. lyrata populations.
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Affiliation(s)
- Ulla Kemi
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
| | - Anne Niittyvuopio
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
| | - Tuomas Toivainen
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
- Biocenter Oulu, University of Oulu, 90014, Oulu, Finland
| | - Anu Pasanen
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
| | - Bénédicte Quilot-Turion
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
- INRA, UR1052 Génétique et Amélioration des Fruits et Légumes, F-84143, Montfavet, France
| | - Karl Holm
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752, 36 Uppsala, Sweden
| | - Ulf Lagercrantz
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752, 36 Uppsala, Sweden
| | - Outi Savolainen
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
- Biocenter Oulu, University of Oulu, 90014, Oulu, Finland
| | - Helmi Kuittinen
- Department of Biology, University of Oulu, PO Box 3000, FIN-90401, Oulu, Finland
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22
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Montesinos-Navarro A, Picó FX, Tonsor SJ. CLINAL VARIATION IN SEED TRAITS INFLUENCING LIFE CYCLE TIMING INARABIDOPSIS THALIANA. Evolution 2012; 66:3417-31. [DOI: 10.1111/j.1558-5646.2012.01689.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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de Casas RR, Kovach K, Dittmar E, Barua D, Barco B, Donohue K. Seed after-ripening and dormancy determine adult life history independently of germination timing. THE NEW PHYTOLOGIST 2012; 194:868-879. [PMID: 22404637 DOI: 10.1111/j.1469-8137.2012.04097.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
• Seed dormancy can affect life history through its effects on germination time. Here, we investigate its influence on life history beyond the timing of germination. • We used the response of Arabidopsis thaliana to chilling at the germination and flowering stages to test the following: how seed dormancy affects germination responses to the environment; whether variation in dormancy affects adult phenology independently of germination time; and whether environmental cues experienced by dormant seeds have an effect on adult life history. • Dormancy conditioned the germination response to low temperatures, such that prolonged periods of chilling induced dormancy in nondormant seeds, but stimulated germination in dormant seeds. The alleviation of dormancy through after-ripening was associated with earlier flowering, independent of germination date. Experimental dormancy manipulations showed that prolonged chilling at the seed stage always induced earlier flowering, regardless of seed dormancy. Surprisingly, this effect of seed chilling on flowering time was observed even when low temperatures did not induce germination. • In summary, seed dormancy influences flowering time and hence life history independent of its effects on germination timing. We conclude that the seed stage has a pronounced effect on life history, the influence of which goes well beyond the timing of germination.
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Affiliation(s)
- Rafael Rubio de Casas
- NESCent, 2024 W. Main Street, Suite A200, Durham, NC 27705, USA
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Katherine Kovach
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Emily Dittmar
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Deepak Barua
- Indian Institute of Science Education and Research, Pune, India
| | - Brenden Barco
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Kathleen Donohue
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
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24
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Challenges in studies on flowering time: interfaces between phenological research and the molecular network of flowering genes. Ecol Res 2011. [DOI: 10.1007/s11284-011-0835-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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DeBolt S. Copy number variation shapes genome diversity in Arabidopsis over immediate family generational scales. Genome Biol Evol 2010; 2:441-53. [PMID: 20624746 PMCID: PMC2997553 DOI: 10.1093/gbe/evq033] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Arabidopsis thaliana is the model plant and is grown worldwide by plant biologists seeking to dissect the molecular underpinning of plant growth and development. Gene copy number variation (CNV) is a common form of genome natural diversity that is currently poorly studied in plants and may have broad implications for model organism research, evolutionary biology, and crop science. Herein, comparative genomic hybridization (CGH) was used to identify and interrogate regions of gene CNV across the A. thaliana genome. A common temperature condition used for growth of A. thaliana in our laboratory and many around the globe is 22 degrees C. The current study sought to test whether A. thaliana, grown under different temperature (16 and 28 degrees C) and stress regimes (salicylic acid spray) for five generations, selecting for fecundity at each generation, displayed any differences in CNV relative to a plant lineage growing under normal conditions. Three siblings from each alternative temperature or stress lineage were also compared with the reference genome (22 degrees C) by CGH to determine repetitive and nonrepetitive CNVs. Findings document exceptional rates of CNV in the genome of A. thaliana over immediate family generational scales. A propensity for duplication and nonrepetitive CNVs was documented in 28 degrees C CGH, which was correlated with the greatest plant stress and infers a potential CNV-environmental interaction. A broad diversity of gene species were observed within CNVs, but transposable elements and biotic stress response genes were notably overrepresented as a proportion of total genes and genes initiating CNVs. Results support a model whereby segmental CNV and the genes encoded within these regions contribute to adaptive capacity of plants through natural genome variation.
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Affiliation(s)
- Seth DeBolt
- Plant Physiology/Biochemistry/Molecular Biology Program, Department of Horticulture, University of Kentucky, USA.
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26
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Brachi B, Faure N, Horton M, Flahauw E, Vazquez A, Nordborg M, Bergelson J, Cuguen J, Roux F. Linkage and association mapping of Arabidopsis thaliana flowering time in nature. PLoS Genet 2010; 6:e1000940. [PMID: 20463887 PMCID: PMC2865524 DOI: 10.1371/journal.pgen.1000940] [Citation(s) in RCA: 305] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 04/06/2010] [Indexed: 12/28/2022] Open
Abstract
Flowering time is a key life-history trait in the plant life cycle. Most studies to unravel the genetics of flowering time in Arabidopsis thaliana have been performed under greenhouse conditions. Here, we describe a study about the genetics of flowering time that differs from previous studies in two important ways: first, we measure flowering time in a more complex and ecologically realistic environment; and, second, we combine the advantages of genome-wide association (GWA) and traditional linkage (QTL) mapping. Our experiments involved phenotyping nearly 20,000 plants over 2 winters under field conditions, including 184 worldwide natural accessions genotyped for 216,509 SNPs and 4,366 RILs derived from 13 independent crosses chosen to maximize genetic and phenotypic diversity. Based on a photothermal time model, the flowering time variation scored in our field experiment was poorly correlated with the flowering time variation previously obtained under greenhouse conditions, reinforcing previous demonstrations of the importance of genotype by environment interactions in A. thaliana and the need to study adaptive variation under natural conditions. The use of 4,366 RILs provides great power for dissecting the genetic architecture of flowering time in A. thaliana under our specific field conditions. We describe more than 60 additive QTLs, all with relatively small to medium effects and organized in 5 major clusters. We show that QTL mapping increases our power to distinguish true from false associations in GWA mapping. QTL mapping also permits the identification of false negatives, that is, causative SNPs that are lost when applying GWA methods that control for population structure. Major genes underpinning flowering time in the greenhouse were not associated with flowering time in this study. Instead, we found a prevalence of genes involved in the regulation of the plant circadian clock. Furthermore, we identified new genomic regions lacking obvious candidate genes.
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Affiliation(s)
- Benjamin Brachi
- Laboratoire Génétique et Evolution des Populations Végétales, Unité Mixte de Recherche CNRS 8016, Université des Sciences et Technologies de Lille 1, Villeneuve d'Ascq, France
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Brock MT, Stinchcombe JR, Weinig C. Indirect effects of FRIGIDA: floral trait (co)variances are altered by seasonally variable abiotic factors associated with flowering time. J Evol Biol 2009; 22:1826-38. [PMID: 19583697 DOI: 10.1111/j.1420-9101.2009.01794.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reproductive timing is a critical life-history event that could influence the (co)variation of traits developing later in ontogeny by regulating exposure to seasonally variable factors. In a field experiment with Arabidopsis thaliana, we explore whether allelic variation at a flowering-time gene of major effect (FRIGIDA) affects (co)variation of floral traits by regulating exposure to photoperiod, temperature, and moisture levels. We detect a positive latitudinal cline in floral organ size among plants with putatively functional FRI alleles. Statistically controlling for bolting day removes the cline, suggesting that seasonal abiotic variation affects floral morphology. Both photoperiod and precipitation at bolting correlate positively with the length of petals, stamens, and pistils. Additionally, floral (co)variances differ significantly across FRI backgrounds, such that the sign of some floral-trait correlations reverses. Subsequent experimental manipulations of photoperiod and water availability demonstrate direct effects of these abiotic factors on floral traits. In sum, these results highlight how the timing of life-history events can affect the expression of traits developing later in ontogeny, and provide some of the first empirical evidence for the effects of major genes on evolutionary potential.
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Affiliation(s)
- M T Brock
- Department of Botany, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, USA.
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28
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Major flowering time gene, flowering locus C, regulates seed germination in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2009; 106:11661-6. [PMID: 19564609 DOI: 10.1073/pnas.0901367106] [Citation(s) in RCA: 220] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Flowering locus C (FLC) is a major regulator of flowering responses to seasonal environmental factors. Here, we document that FLC also regulates another major life-history transition-seed germination, and that natural variation at the FLC locus and in FLC expression is associated with natural variation in temperature-dependent germination. FLC-mediated germination acts through additional genes in the flowering pathway (FT, SOC1, and AP1) before involving the abscisic acid catabolic pathway (via CYP707A2) and gibberellins biosynthetic pathway (via GA20ox1) in seeds. Also, FLC regulation of germination is largely maternally controlled, with FLC peaking and FT, SOC1, and AP1 levels declining at late stages of seed maturation. High FLC expression during seed maturation is associated with altered expression of hormonal genes (CYP707A2 and GA20ox1) in germinating seeds, indicating that gene expression before the physiological independence of seeds can influence gene expression well after any physical connection between maternal plants and seeds exists. The major role of FLC in temperature-dependent germination documented here reveals a much broader adaptive significance of natural variation in FLC. Therefore, pleiotropy between these major life stages likely influences patterns of natural selection on this important gene, making FLC a promising case for examining how pleiotropy influences adaptive evolution.
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Donohue K. Completing the cycle: maternal effects as the missing link in plant life histories. Philos Trans R Soc Lond B Biol Sci 2009; 364:1059-74. [PMID: 19324611 PMCID: PMC2666684 DOI: 10.1098/rstb.2008.0291] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Maternal effects on seed traits such as germination are important components of the life histories of plants because they represent the pathway from adult to offspring: the pathway that completes the life cycle. Maternal environmental effects on germination influence basic life-history expression, natural selection on germination, the expression of genetic variation for germination and even the genes involved in germination. Maternal effects on seed traits can even influence generation time and projected population growth rates. Whether these maternal environmental effects are imposed by the maternal genotype, the endosperm genotype or the embryonic genotype, however, is as yet unknown. Patterns of gene expression and protein synthesis in seeds indicate that the maternal genotype has the opportunity to influence its progeny's germination behaviour. Investigation of the phenotypic consequences of maternal environmental effects, regardless of its genetic determination, is relevant for understanding the variation in plant life cycles. Distinguishing the genotype(s) that control them is relevant for predicting the evolutionary trajectories and patterns of selection on progeny phenotypes and the genes underlying them.
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Affiliation(s)
- Kathleen Donohue
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA.
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Simon M, Loudet O, Durand S, Bérard A, Brunel D, Sennesal FX, Durand-Tardif M, Pelletier G, Camilleri C. Quantitative trait loci mapping in five new large recombinant inbred line populations of Arabidopsis thaliana genotyped with consensus single-nucleotide polymorphism markers. Genetics 2008; 178:2253-64. [PMID: 18430947 PMCID: PMC2323813 DOI: 10.1534/genetics.107.083899] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 01/30/2008] [Indexed: 12/25/2022] Open
Abstract
Quantitative approaches conducted in a single mapping population are limited by the extent of genetic variation distinguishing the parental genotypes. To overcome this limitation and allow a more complete dissection of the genetic architecture of complex traits, we built an integrated set of 15 new large Arabidopsis thaliana recombinant inbred line (RIL) populations optimized for quantitative trait loci (QTL) mapping, having Columbia as a common parent crossed to distant accessions. Here we present 5 of these populations that were validated by investigating three traits: flowering time, rosette size, and seed production as an estimate of fitness. The large number of RILs in each population (between 319 and 377 lines) and the high density of evenly spaced genetic markers scored ensure high power and precision in QTL mapping even under a minimal phenotyping framework. Moreover, the use of common markers across the different maps allows a direct comparison of the QTL detected within the different RIL sets. In addition, we show that following a selective phenotyping strategy by performing QTL analyses on genotypically chosen subsets of 164 RILs (core populations) does not impair the power of detection of QTL with phenotypic contributions >7%.
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Affiliation(s)
- Matthieu Simon
- Station de Génétique et d'Amélioration des Plantes UR254, INRA, F-78000 Versailles, France
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Donohue K, Heschel MS, Butler CM, Barua D, Sharrock RA, Whitelam GC, Chiang GCK. Diversification of phytochrome contributions to germination as a function of seed-maturation environment. THE NEW PHYTOLOGIST 2008; 177:367-379. [PMID: 18028293 DOI: 10.1111/j.1469-8137.2007.02281.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Environmental conditions during seed maturation influence germination, but the genetic basis of maternal environmental effects on germination is virtually unknown. Using single and multiple mutants of phytochromes, it is shown here that different phytochromes contributed to germination differently, depending on seed-maturation conditions. Arabidopsis thaliana wild-type seeds that were matured under cool temperatures were intensely dormant compared with seeds matured at warmer temperature, and this dormancy was broken only after warm seed-stratification followed by cold seed-stratification. The warm-cold stratification broke dormancy in fresh seeds but not in dry after-ripened seeds. Functional PHYB and PHYD were necessary to break cool-induced dormancy, which indicates a previously unknown and ecologically important function for PHYD. Disruption of PHYA in combination with PHYD (but not PHYB) restored germination to near wild-type levels, indicating that PHYA contributes to the maintenance of cool-induced dormancy on a phyD background. Effects of seed-maturation temperature were much stronger than effects of seed-maturation photoperiod. PHYB contributed to germination somewhat more strongly in seeds matured under short days, whereas PHYD contributed to germination somewhat more strongly in seeds matured under long days. The variable contributions of different phytochromes to germination as a function of seed-maturation conditions reveal further functional diversification of the phytochromes during the process of germination. This study identifies among the first genes to be associated with maternal environmental effects on germination.
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Affiliation(s)
- Kathleen Donohue
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, MA 02138, USA
| | - M Shane Heschel
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, MA 02138, USA
| | - Colleen M Butler
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, MA 02138, USA
| | - Deepak Barua
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, MA 02138, USA
| | - Robert A Sharrock
- Department of Plant Sciences and Plant Pathology, Montana State University, PO Box 173150, Bozeman, MT 59717-3150, USA
| | - Garry C Whitelam
- Institute of Genetics, Adrian Building, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - George C K Chiang
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, MA 02138, USA
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32
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Botto JF, Coluccio MP. Seasonal and plant-density dependency for quantitative trait loci affecting flowering time in multiple populations of Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2007; 30:1465-79. [PMID: 17897416 DOI: 10.1111/j.1365-3040.2007.01722.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Multiple environmental cues regulate the transition to flowering. In natural environments, plants perceive seasonal progression by changes in day length and growth temperature, and plant density is monitored by changes in the light quality reflected from neighbouring vegetation. To understand the seasonal and plant-density dependence associated with natural allelic variation in flowering time, we conducted a quantitative trait loci (QTL) mapping study in Ler x Cvi, Bay x Sha and Ler x No-0 recombinant inbred line (RIL) populations of Arabidopsis thaliana. Days and total leaf number to bolting were examined under low and high plant density (200 or 1600 plants m(-2)) in autumn-winter and spring seasons. We found between 4 and 10 QTLs associated with seasonal and density variations in each RIL population. For Ler x Cvi and Bay x Sha RIL populations, a major proportion of QTLs showed seasonal and density interaction (up to 63%) and four QTLs were common to all environments (21%). Only three QTLs showed seasonal or density dependency. By aligning the linkage maps onto a common physical map, we detected at least one QTL at chromosome 2 and two QTLs at chromosome 5 that overlap between the three RIL populations, suggesting that these QTLs play a crucial role in the adaptive control of flowering time.
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Affiliation(s)
- Javier F Botto
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, Av San Martín 4453, C1417DSE Ciudad de Buenos Aires, Argentina.
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Heschel MS, Selby J, Butler C, Whitelam GC, Sharrock RA, Donohue K. A new role for phytochromes in temperature-dependent germination. THE NEW PHYTOLOGIST 2007; 174:735-741. [PMID: 17504457 DOI: 10.1111/j.1469-8137.2007.02044.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Germination timing is a fundamental life-history trait, as seedling establishment predicates realized fitness in the wild. Light and temperature are two important cues by which seeds sense the proper season of germination. Using Arabidopsis thaliana, we provide evidence that phytochrome-mediated germination pathways simultaneously respond to light and temperature cues in ways that affect germination. Phytochrome mutant seeds were sown on agar plates and allowed to germinate in lit, growth chambers across a range of temperatures (7 degrees C to 28 degrees C). phyA had an important role in promoting germination at warmer temperatures, phyE was important to germination at colder temperatures and phyB was important to germination across a range of temperatures. Different phytochromes were required for germination at different temperatures, indicating a restriction or even a potential specialization of individual phytochrome activity as a function of temperature. This temperature-dependent activity of particular phytochromes reveals a potentially novel role for phytochrome pathways in regulating the seasonal timing of germination.
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Affiliation(s)
- M Shane Heschel
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA 02138, USA
- Present address: Department of Biology, Colorado College, 14 East Cache La Poudre Street, Colorado Springs, CO 80903, USA
| | - Jessica Selby
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA 02138, USA
| | - Colleen Butler
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA 02138, USA
| | - Garry C Whitelam
- Department of Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Robert A Sharrock
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3140, USA
| | - Kathleen Donohue
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA 02138, USA
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Schläppi MR. FRIGIDA LIKE 2 is a functional allele in Landsberg erecta and compensates for a nonsense allele of FRIGIDA LIKE 1. PLANT PHYSIOLOGY 2006; 142:1728-38. [PMID: 17056759 PMCID: PMC1676065 DOI: 10.1104/pp.106.085571] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Landsberg erecta (Ler) accession of Arabidopsis (Arabidopsis thaliana) has a weak allele of the floral inhibitor FLOWERING LOCUS C (FLC). FLC-Ler is weakly up-regulated by the active San Feliu-2 (Sf2) allele of FRIGIDA (FRI-Sf2), resulting in a moderately late-flowering phenotype. By contrast, the Columbia (Col) allele of FLC is strongly up-regulated by FRI-Sf2, resulting in a very late-flowering phenotype. In Col, the FRI-related gene FRI LIKE 1 (FRL1) is required for FRI-mediated up-regulation of FLC. It is shown here that in Ler, the FRL1-related gene FRI LIKE 2 (FRL2), but not FRL1, is required for FRI-mediated up-regulation of FLC. FRL1-Ler is shown to be a nonsense allele of FRL1 due to a naturally occurring premature stop codon in the middle of the conceptual protein sequence, suggesting that FRL1-Ler is nonfunctional. Compared to FRL2-Col, FRL2-Ler has two amino acid changes in the conceptual protein sequence. Plants homozygous for FRI-Sf2, FLC-Ler, FRL1-Ler, and FRL2-Col have no detectable FLC expression, resulting in an extremely early flowering phenotype. Transformation of a genomic fragment of FRL2-Ler, but not of FRL2-Col, into a recombinant inbred line derived from these plants restores both FRI-mediated up-regulation of FLC expression and a late-flowering phenotype, indicating that FRL2-Ler is the functional allele of FRL2. Taken together, these results suggest that in the two different Arabidopsis accessions Col and Ler, either FRL1 or FRL2, but not both, is functional and required for FRI-mediated up-regulation of FLC.
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Affiliation(s)
- Michael R Schläppi
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, USA.
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Weinig C, Brock MT, Dechaine JA, Welch SM. Resolving the genetic basis of invasiveness and predicting invasions. Genetica 2006; 129:205-16. [PMID: 16955329 DOI: 10.1007/s10709-006-9015-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Accepted: 06/18/2006] [Indexed: 11/28/2022]
Abstract
Considerable effort has been invested in determining traits underlying invasiveness. Yet, identifying a set of traits that commonly confers invasiveness in a range of species has proven elusive, and almost nothing is known about genetic loci affecting invasive success. Incorporating genetic model organisms into ecologically relevant studies is one promising avenue to begin dissecting the genetic underpinnings of invasiveness. Molecular biologists are rapidly characterizing genes mediating developmental responses to diverse environmental cues, i.e., genes for plasticity, as well as to environmental factors likely to impose strong selection on invading species, e.g., resistance to herbivores and competitors, coordination of life-history events with seasonal changes, and physiological tolerance of heat, drought, or cold. Here, we give an overview of molecular genetic tools increasingly used to characterize the genetic basis of adaptation and that may be used to begin identifying genetic mechanisms of invasiveness. Given the divergent traits that affect invasiveness, "invasiveness genes" common to many clades are unlikely, but the combination of developmental genetic advances with further evolutionary studies and modeling may provide a framework for identifying genes that account for invasiveness in related species.
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Affiliation(s)
- Cynthia Weinig
- Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Avenue, St Paul, MN 55108, USA.
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36
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Ehrenreich IM, Purugganan MD. The molecular genetic basis of plant adaptation. AMERICAN JOURNAL OF BOTANY 2006; 93:953-962. [PMID: 21642159 DOI: 10.3732/ajb.93.7.953] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
How natural selection on adaptive traits is filtered to the genetic level remains largely unknown. Theory and quantitative trait locus (QTL) mapping have provided insights into the number and effect of genes underlying adaptations, but these results have been hampered by questions of applicability to real biological systems and poor resolution, respectively. Advances in molecular technologies have expedited the cloning of adaptive genes through both forward and reverse genetic approaches. Forward approaches start with adaptive traits and attempt to characterize their underlying genetic architectures through linkage disequilibrium mapping, QTL mapping, and other methods. Reverse screens search large sequence data sets for genes that possess the signature of selection. Though both approaches have been successful in identifying adaptive genes in plants, very few, if any, of these adaptations' molecular bases have been fully resolved. The continued isolation of plant adaptive genes will lead to a more comprehensive understanding of natural selection's effect on genes and genomes.
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Affiliation(s)
- Ian M Ehrenreich
- Department of Genetics, Box 7614, North Carolina State University, Raleigh, North Carolina 27695 USA
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37
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Le Corre V. Variation at two flowering time genes within and among populations of Arabidopsis thaliana: comparison with markers and traits. Mol Ecol 2006; 14:4181-92. [PMID: 16262868 DOI: 10.1111/j.1365-294x.2005.02722.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Flowering Locus C (FLC) and Frigida are two interacting genes controlling flowering time variation in Arabidopsis thaliana. Variation at these genes was surveyed in 12 A. thaliana populations sampled in France. These populations were also screened for variation at molecular markers [12 microsatellites and 19 cleaved amplified polymorphic sequence (CAPS) markers] and at seven quantitative traits measured with and without vernalization. Seven populations were highly polymorphic at markers (H(S) = 0.57 at microsatellites, 0.24 at CAPS) and showed heritable variation for bolting time and some other traits. Five populations were genetically fixed or nearly fixed. Q(ST) for bolting time without vernalization was significantly higher than F(ST), suggesting local divergent selection. One of the two haplotype groups at FLC (FLC(A)) was very predominant (frequency of 99%). The first exon of Frigida showed elevated nonsynonymous variation, and nine loss-of-function mutations were found throughout the gene. The association between loss-of-function and earlier bolting was confirmed. Overall, 18 Frigida haplotypes were detected. The pattern of variation at Frigida was largely similar to that found at markers and traits, with the same populations being fixed or highly diverse. Metapopulation dynamics is thus probably the main factor shaping genetic variation in A. thaliana. However, F(ST) for functional (FRI) vs. nonfunctional (FRI(Delta)) haplotypes was significantly higher than F(ST) at markers. This suggested that loss-of-function at Frigida is under local selection for flowering time.
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Affiliation(s)
- V Le Corre
- UMR Biologie et Gestion des Adventices, INRA, BP 86510, 21065 Dijon cedex, France.
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38
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Toomajian C, Hu TT, Aranzana MJ, Lister C, Tang C, Zheng H, Zhao K, Calabrese P, Dean C, Nordborg M. A nonparametric test reveals selection for rapid flowering in the Arabidopsis genome. PLoS Biol 2006; 4:e137. [PMID: 16623598 PMCID: PMC1440937 DOI: 10.1371/journal.pbio.0040137] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 02/28/2006] [Indexed: 11/18/2022] Open
Abstract
The detection of footprints of natural selection in genetic polymorphism data is fundamental to understanding the genetic basis of adaptation, and has important implications for human health. The standard approach has been to reject neutrality in favor of selection if the pattern of variation at a candidate locus was significantly different from the predictions of the standard neutral model. The problem is that the standard neutral model assumes more than just neutrality, and it is almost always possible to explain the data using an alternative neutral model with more complex demography. Today's wealth of genomic polymorphism data, however, makes it possible to dispense with models altogether by simply comparing the pattern observed at a candidate locus to the genomic pattern, and rejecting neutrality if the pattern is extreme. Here, we utilize this approach on a truly genomic scale, comparing a candidate locus to thousands of alleles throughout the Arabidopsis thaliana genome. We demonstrate that selection has acted to increase the frequency of early-flowering alleles at the vernalization requirement locus FRIGIDA. Selection seems to have occurred during the last several thousand years, possibly in response to the spread of agriculture. We introduce a novel test statistic based on haplotype sharing that embraces the problem of population structure, and so should be widely applicable.
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Affiliation(s)
- Christopher Toomajian
- Molecular and Computational Biology, University of Southern California, Los Angeles, California, USA.
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39
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Jakobsson M, Hagenblad J, Tavaré S, Säll T, Halldén C, Lind-Halldén C, Nordborg M. A unique recent origin of the allotetraploid species Arabidopsis suecica: Evidence from nuclear DNA markers. Mol Biol Evol 2006; 23:1217-31. [PMID: 16549398 DOI: 10.1093/molbev/msk006] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A coalescent-based method was used to investigate the origins of the allotetraploid Arabidopsis suecica, using 52 nuclear microsatellite loci typed in eight individuals of A. suecica and 14 individuals of its maternal parent Arabidopsis thaliana, and four short fragments of genomic DNA sequenced in a sample of four individuals of A. suecica and in both its parental species A. thaliana and Arabidopsis arenosa. All loci were variable in A. thaliana but only 24 of the 52 microsatellite loci and none of the four sequence fragments were variable in A. suecica. We explore a number of possible evolutionary scenarios for A. suecica and conclude that it is likely that A. suecica has a recent, unique origin between 12,000 and 300,000 years ago. The time estimates depend strongly on what is assumed about population growth and rates of mutation. When combined with what is known about the history of glaciations, our results suggest that A. suecica originated south of its present distribution in Sweden and Finland and then migrated north, perhaps in the wake of the retreating ice.
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Affiliation(s)
- Mattias Jakobsson
- Bioinformatics Program, Department of Human Genetics, University of Michigan, USA.
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Stinchcombe JR, Caicedo AL, Hopkins R, Mays C, Boyd EW, Purugganan MD, Schmitt J. Vernalization sensitivity in Arabidopsis thaliana (Brassicaceae): the effects of latitude and FLC variation. AMERICAN JOURNAL OF BOTANY 2005; 92:1701-1707. [PMID: 21646087 DOI: 10.3732/ajb.92.10.1701] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Latitudinal variation in climate is predicted to select for latitudinal differentiation in sensitivity to the environmental cues that signal plants to flower at the appropriate time for a given climate. In Arabidopsis thaliana, flowering is promoted by exposure to cold temperatures (vernalization), and several vernalization pathway loci are known. To test whether natural variation in vernalization sensitivity could account for a previously observed latitudinal cline in flowering time in A. thaliana, we exposed 21 European accessions to 0, 10, 20, or 30 d of vernalization and observed leaf number at flowering under short days in a growth chamber. We observed a significant latitudinal cline in vernalization sensitivity: southern accessions were more sensitive to vernalization than northern accessions. In addition, accessions that were late flowering in the absence of vernalization were more sensitive to vernalization cues. Allelic variation at the flowering time regulatory gene FLC was not associated with mean vernalization sensitivity, but one allele class exhibited greater variance in vernalization sensitivity.
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Affiliation(s)
- John R Stinchcombe
- Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912 USA
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41
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Riihimäki M, Podolsky R, Kuittinen H, Koelewijn H, Savolainen O. Studying genetics of adaptive variation in model organisms: flowering time variation in Arabidopsis lyrata. Genetica 2005; 123:63-74. [PMID: 15881681 DOI: 10.1007/s10709-003-2711-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Arabidopsis thaliana has emerged as a model organism for plant developmental genetics, but it is also now being widely used for population genetic studies. Outcrossing relatives of A. thaliana are likely to provide suitable additional or alternative species for studies of evolutionary and population genetics. We have examined patterns of adaptive flowering time variation in the outcrossing, perennial A. lyrata. In addition, we examine the distribution of variation at marker genes in populations form North America and Europe. The probability of flowering in this species differs between southern and northern populations. Northern populations are much less likely to flower in short than in long days. A significant daylength by region interaction shows that the northern and southern populations respond differently to the daylength. The timing of flowering also differs between populations, and is made shorter by long days, and in some populations, by vernalization. North American and European populations show consistent genetic differentiation over microsatellite and isozyme loci and alcohol dehydrogenase sequences. Thus, the patterns of variation are quite different from those in A. thaliana, where flowering time differences show little relationship to latitude of origin and the genealogical trees of accessions vary depending on the genomic region studied. The genetic architecture of adaptation can be compared in these species with different life histories.
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Affiliation(s)
- Mona Riihimäki
- Department of Biology, University of Oulu, FIN-90014, Finland
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42
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Shindo C, Aranzana MJ, Lister C, Baxter C, Nicholls C, Nordborg M, Dean C. Role of FRIGIDA and FLOWERING LOCUS C in determining variation in flowering time of Arabidopsis. PLANT PHYSIOLOGY 2005; 138:1163-73. [PMID: 15908596 PMCID: PMC1150429 DOI: 10.1104/pp.105.061309] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) accessions provide an excellent resource to dissect the molecular basis of adaptation. We have selected 192 Arabidopsis accessions collected to represent worldwide and local variation and analyzed two adaptively important traits, flowering time and vernalization response. There was huge variation in the flowering habit of the different accessions, with no simple relationship to latitude of collection site and considerable diversity occurring within local regions. We explored the contribution to this variation from the two genes FRIGIDA (FRI) and FLOWERING LOCUS C (FLC), previously shown to be important determinants in natural variation of flowering time. A correlation of FLC expression with flowering time and vernalization was observed, but it was not as strong as anticipated due to many late-flowering/vernalization-requiring accessions being associated with low FLC expression and early-flowering accessions with high FLC expression. Sequence analysis of FRI revealed which accessions were likely to carry functional alleles, and, from comparison of flowering time with allelic type, we estimate that approximately 70% of flowering time variation can be accounted for by allelic variation of FRI. The maintenance and propagation of 20 independent nonfunctional FRI haplotypes suggest that the loss-of-function mutations can confer a strong selective advantage. Accessions with a common FRI haplotype were, in some cases, associated with very different FLC levels and wide variation in flowering time, suggesting additional variation at FLC itself or other genes regulating FLC. These data reveal how useful these Arabidopsis accessions will be in dissecting the complex molecular variation that has led to the adaptive phenotypic variation in flowering time.
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Affiliation(s)
- Chikako Shindo
- Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
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Wender NJ, Polisetty CR, Donohue K. Density-dependent processes influencing the evolutionary dynamics of dispersal: a functional analysis of seed dispersal in Arabidopsis thaliana (Brassicaceae). AMERICAN JOURNAL OF BOTANY 2005; 92:960-971. [PMID: 21652479 DOI: 10.3732/ajb.92.6.960] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We conducted a functional analysis of seed dispersal and its plasticity in response to density in Arabidopsis thaliana by growing morphologically diverse ecotypes under high and low density and measuring seed dispersion patterns under controlled conditions. Maternal plant architectural traits such as height and branching, and fruit traits such as dehiscence and silique length influenced various measures of seed dispersion patterns, including the average dispersal distance, kurtosis of the seed dispersion pattern, and post-dispersal seed density. The density at which plants grew determined which traits influenced dispersal. A change in density would therefore change which maternal characters would be subjected to natural selection through selection on dispersal. Density-mediated maternal effects on dispersal contributed to a negative correlation between parents and offspring for sibling density after dispersal, which could impede the response to selection on post-dispersal sibling density. Plant traits that influenced dispersal also influenced maternal fitness- sometimes opposing selection on dispersal and sometimes augmenting it-and the direction of the relationship sometimes depended on density. These density-dependent relationships between plant traits, dispersal, and maternal fitness can increase or reduce evolutionary constraints on dispersal, depending on the trait and depending on post-dispersal density itself.
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Affiliation(s)
- Naomi J Wender
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Ave., Cambridge, Massachusetts 02138 USA
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Werner JD, Borevitz JO, Uhlenhaut NH, Ecker JR, Chory J, Weigel D. FRIGIDA-independent variation in flowering time of natural Arabidopsis thaliana accessions. Genetics 2005; 170:1197-207. [PMID: 15911588 PMCID: PMC1451178 DOI: 10.1534/genetics.104.036533] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
FRIGIDA (FRI) and FLOWERING LOCUS C (FLC) are two genes that, unless plants are vernalized, greatly delay flowering time in Arabidopsis thaliana. Natural loss-of-function mutations in FRI cause the early flowering growth habits of many A. thaliana accessions. To quantify the variation among wild accessions due to FRI, and to identify additional genetic loci in wild accessions that influence flowering time, we surveyed the flowering times of 145 accessions in long-day photoperiods, with and without a 30-day vernalization treatment, and genotyped them for two common natural lesions in FRI. FRI is disrupted in at least 84 of the accessions, accounting for only approximately 40% of the flowering-time variation in long days. During efforts to dissect the causes for variation that are independent of known dysfunctional FRI alleles, we found new loss-of-function alleles in FLC, as well as late-flowering alleles that do not map to FRI or FLC. An FLC nonsense mutation was found in the early flowering Van-0 accession, which has otherwise functional FRI. In contrast, Lz-0 flowers late because of high levels of FLC expression, even though it has a deletion in FRI. Finally, eXtreme array mapping identified genomic regions linked to the vernalization-independent, late-flowering habit of Bur-0, which has an alternatively spliced FLC allele that behaves as a null allele.
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Affiliation(s)
- Jonathan D. Werner
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
- Department of Biology, University of California, San Diego, California 92037
| | - Justin O. Borevitz
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
- Department of Biology, University of California, San Diego, California 92037
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637
| | - N. Henriette Uhlenhaut
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Joseph R. Ecker
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
- Salk Institute, Genome Analysis Laboratory, La Jolla, California 92037
| | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Detlef Weigel
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
- Corresponding author: MPI for Developmental Biology, Spemannstrasse 37-39, D-72076 Tübingen, Germany. E-mail:
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DONOHUE KATHLEEN, DORN LISA, GRIFFITH CONVERSE, KIM EUNSUK, AGUILERA ANNA, POLISETTY CHANDRAR, SCHMITT JOHANNA. THE EVOLUTIONARY ECOLOGY OF SEED GERMINATION OF ARABIDOPSIS THALIANA: VARIABLE NATURAL SELECTION ON GERMINATION TIMING. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01751.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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DONOHUE KATHLEEN, DORN LISA, GRIFFITH CONVERSE, KIM EUNSUK, AGUILERA ANNA, POLISETTY CHANDRAR, SCHMITT JOHANNA. NICHE CONSTRUCTION THROUGH GERMINATION CUEING: LIFE-HISTORY RESPONSES TO TIMING OF GERMINATION IN ARABIDOPSIS THALIANA. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01752.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Callahan HS, Dhanoolal N, Ungerer MC. Plasticity genes and plasticity costs: a new approach using an Arabidopsis recombinant inbred population. THE NEW PHYTOLOGIST 2005; 166:129-139. [PMID: 15760357 DOI: 10.1111/j.1469-8137.2005.01368.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Earlier flowering is triggered by vernalization in some but not all Arabidopsis ecotypes, often reflecting allelic variation at the FRIGIDA (FRI) locus. Using a recombinant inbred (RI) population polymorphic at FRI, we examined fitness consequences of variation for plasticity. Flowering and fitness were scored for 68 RI genotypes following full and partial vernalization treatments. Within-environment and mixed-model anovas estimated variance components for a genotype effect and a G x E term, respectively. Selection analyses examined whether delayed bolting increases fitness; a plasticity costs analysis asked whether increased plasticity lowers fitness. We also explored whether trait QTL had environment-specific effects, colocated in the immediate vicinity of FRI, or overlapped with fitness QTL. Selection may favor fri alleles and constitutive early flowering, especially in conditions that only partially vernalize plants. Plasticity costs, detected only after partial vernalization and only marginally significant, were nonetheless consistent with FRI-FLC function. We discuss how information about QTL with environment-specific effects, fitness QTL, and knowledge about plasticity genes can improve interpretation of selection or plasticity cost analyses.
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Affiliation(s)
- Hilary S Callahan
- Department of Biological Sciences, 3009 Broadway, Barnard College, Columbia University, 3009 Broadway, New York, NY 10027-6598, USA.
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Donohue K. Niche construction through phenological plasticity: life history dynamics and ecological consequences. THE NEW PHYTOLOGIST 2005; 166:83-92. [PMID: 15760353 DOI: 10.1111/j.1469-8137.2005.01357.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ability of an organism to alter the environment that it experiences has been termed 'niche construction'. Plants have several ways whereby they can determine the environment to which they are exposed at different life stages. This paper discusses three of these: plasticity in dispersal, flowering timing and germination timing. It reviews pathways through which niche construction alters evolutionary and ecological trajectories by altering the selective environment to which organisms are exposed, the phenotypic expression of plastic characters, and the expression of genetic variation. It provides examples whereby niche construction creates positive or negative feedbacks between phenotypes and environments, which in turn cause novel evolutionary constraints and novel life-history expression.
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Affiliation(s)
- Kathleen Donohue
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA 02138, USA.
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Donohue K, Dorn L, Griffith C, Kim E, Aguilera A, Polisetty CR, schmitt J. ENVIRONMENTAL AND GENETIC INFLUENCES ON THE GERMINATION OF ARABIDOPSIS THALLANA IN THE FIELD. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01750.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Donohue K, Polisetty CR, Wender NJ. Genetic basis and consequences of niche construction: plasticity-induced genetic constraints on the evolution of seed dispersal in Arabidopsis thaliana. Am Nat 2005; 165:537-50. [PMID: 15795851 DOI: 10.1086/429162] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Accepted: 12/21/2004] [Indexed: 11/03/2022]
Abstract
Because seed dispersal influences the environment experienced by seeds, that environment can change as dispersal evolves. The evolutionary potential of dispersal can in turn change as dispersal evolves, if its expression of genetic variation depends on the postdispersal environment. We examined whether seed dispersion patterns have a detectable genetic basis (and therefore evolutionary potential) and determined whether that genetic basis changed depending on one postdispersal environmental factor: conspecific density. We grew replicates of 12 ecotypes of Arabidopsis thaliana at high and low density and measured seed dispersion patterns and maternal traits associated with dispersal under controlled conditions. We found density-dependent ecotypic variation for maternal traits that influence dispersal. Significant genetic variation for postdispersal sibling density was detected only when plants were grown at high density, suggesting that if dispersal evolves to result in lower postdispersal densities, the expression of genetic variation for dispersal would be reduced. This dynamic could lead to a plasticity-induced constraint on the evolution of dispersal. The ability of organisms to alter the environment they experience and the ability of that environment to evolve can alter evolutionary dynamics by augmenting or reducing evolutionary potential and thereby facilitating or constraining evolutionary responses to selection.
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Affiliation(s)
- Kathleen Donohue
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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