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Menard GN, Bryant FM, Kelly AA, Craddock CP, Lavagi I, Hassani-Pak K, Kurup S, Eastmond PJ. Natural variation in acyl editing is a determinant of seed storage oil composition. Sci Rep 2018; 8:17346. [PMID: 30478395 PMCID: PMC6255774 DOI: 10.1038/s41598-018-35136-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 10/26/2018] [Indexed: 01/09/2023] Open
Abstract
Seeds exhibit wide variation in the fatty acid composition of their storage oil. However, the genetic basis of this variation is only partially understood. Here we have used a multi-parent advanced generation inter-cross (MAGIC) population to study the genetic control of fatty acid chain length in Arabidopsis thaliana seed oil. We mapped four quantitative trait loci (QTL) for the quantity of the major very long chain fatty acid species 11-eicosenoic acid (20:1), using multiple QTL modelling. Surprisingly, the main-effect QTL does not coincide with FATTY ACID ELONGASE 1 and a parallel genome wide association study suggested that LYSOPHOSPHATIDYLCHOLINE ACYLTRANSFERASE 2 (LPCAT2) is a candidate for this QTL. Regression analysis also suggested that LPCAT2 expression and 20:1 content in seeds of the 19 MAGIC founder accessions are related. LPCAT is a key component of the Lands cycle; an acyl editing pathway that enables acyl-exchange between the acyl-Coenzyme A and phosphatidylcholine precursor pools used for microsomal fatty acid elongation and desaturation, respectively. We Mendelianised the main-effect QTL using biparental chromosome segment substitution lines and carried out complementation tests to show that a single cis-acting polymorphism in the LPCAT2 promoter causes the variation in seed 20:1 content, by altering the LPCAT2 expression level and total LPCAT activity in developing siliques. Our work establishes that oilseed species exhibit natural variation in the enzymic capacity for acyl editing and this contributes to the genetic control of storage oil composition.
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Affiliation(s)
- Guillaume N Menard
- Department of Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Fiona M Bryant
- Department of Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Amélie A Kelly
- Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig Weg 11, 37077, Göttingen, Germany
| | - Christian P Craddock
- Mt. San Jacinto College, Menifee Valley Campus, 28237 La Piedra Road, Menifee, CA, 92584, USA
| | - Irene Lavagi
- Department of Microbiology and Plant Pathology, University of California Riverside, Riverside, CA, 92521, USA
| | - Keywan Hassani-Pak
- Department of Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Smita Kurup
- Department of Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Peter J Eastmond
- Department of Plant Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
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Knoch D, Riewe D, Meyer RC, Boudichevskaia A, Schmidt R, Altmann T. Genetic dissection of metabolite variation in Arabidopsis seeds: evidence for mQTL hotspots and a master regulatory locus of seed metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1655-1667. [PMID: 28338798 PMCID: PMC5444479 DOI: 10.1093/jxb/erx049] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To gain insight into genetic factors controlling seed metabolic composition and its relationship to major seed properties, an Arabidopsis recombinant inbred line (RIL) population, derived from accessions Col-0 and C24, was studied using an MS-based metabolic profiling approach. Relative intensities of 311 polar primary metabolites were used to identify associated genomic loci and to elucidate their interactions by quantitative trait locus (QTL) mapping. A total of 786 metabolic QTLs (mQTLs) were unequally distributed across the genome, forming several hotspots. For the branched-chain amino acid leucine, mQTLs and candidate genes were elucidated in detail. Correlation studies displayed links between metabolite levels, seed protein content, and seed weight. Principal component analysis revealed a clustering of samples, with PC1 mapping to a region on the short arm of chromosome IV. The overlap of this region with mQTL hotspots indicates the presence of a potential master regulatory locus of seed metabolism. As a result of database queries, a series of candidate regulatory genes, including bZIP10, were identified within this region. Depending on the search conditions, metabolic pathway-derived candidate genes for 40-61% of tested mQTLs could be determined, providing an extensive basis for further identification and characterization of hitherto unknown genes causal for natural variation of Arabidopsis seed metabolism.
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Affiliation(s)
- Dominic Knoch
- Department of Molecular Genetics/Heterosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
| | - David Riewe
- Department of Molecular Genetics/Heterosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
| | - Rhonda Christiane Meyer
- Department of Molecular Genetics/Heterosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
| | - Anastassia Boudichevskaia
- Department of Breeding Research/Genome Plasticity, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
| | - Renate Schmidt
- Department of Breeding Research/Genome Plasticity, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
| | - Thomas Altmann
- Department of Molecular Genetics/Heterosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany
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Branham SE, Wright SJ, Reba A, Linder CR. Genome-Wide Association Study of Arabidopsis thaliana Identifies Determinants of Natural Variation in Seed Oil Composition. J Hered 2016; 107:248-56. [PMID: 26704140 PMCID: PMC4885229 DOI: 10.1093/jhered/esv100] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/24/2015] [Indexed: 01/14/2023] Open
Abstract
The renewable source of highly reduced carbon provided by plant triacylglycerols (TAGs) fills an ever increasing demand for food, biodiesel, and industrial chemicals. Each of these uses requires different compositions of fatty acid proportions in seed oils. Identifying the genes responsible for variation in seed oil composition in nature provides targets for bioengineering fatty acid proportions optimized for various industrial and nutrition goals. Here, we characterized the seed oil composition of 391 world-wide, wild accessions of Arabidopsis thaliana, and performed a genome-wide association study (GWAS) of the 9 major fatty acids in the seed oil and 4 composite measures of the fatty acids. Four to 19 regions of interest were associated with the seed oil composition traits. Thirty-four of the genes in these regions are involved in lipid metabolism or transport, with 14 specific to fatty acid synthesis or breakdown. Eight of the genes encode transcription factors. We have identified genes significantly associated with variation in fatty acid proportions that can be used as a resource across the Brassicaceae. Two-thirds of the regions identified contain candidate genes that have never been implicated in lipid metabolism and represent potential new targets for bioengineering.
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Affiliation(s)
- Sandra E Branham
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO 63130 (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX 78712 (Branham, Reba, and Linder).
| | - Sara J Wright
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO 63130 (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX 78712 (Branham, Reba, and Linder)
| | - Aaron Reba
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO 63130 (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX 78712 (Branham, Reba, and Linder)
| | - C Randal Linder
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO 63130 (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX 78712 (Branham, Reba, and Linder)
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Branham SE, Wright SJ, Reba A, Morrison GD, Linder CR. Genome-Wide Association Study in Arabidopsis thaliana of Natural Variation in Seed Oil Melting Point: A Widespread Adaptive Trait in Plants. J Hered 2016; 107:257-65. [PMID: 26865732 DOI: 10.1093/jhered/esw008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/27/2016] [Indexed: 12/29/2022] Open
Abstract
Seed oil melting point is an adaptive, quantitative trait determined by the relative proportions of the fatty acids that compose the oil. Micro- and macro-evolutionary evidence suggests selection has changed the melting point of seed oils to covary with germination temperatures because of a trade-off between total energy stores and the rate of energy acquisition during germination under competition. The seed oil compositions of 391 natural accessions of Arabidopsis thaliana, grown under common-garden conditions, were used to assess whether seed oil melting point within a species varied with germination temperature. In support of the adaptive explanation, long-term monthly spring and fall field temperatures of the accession collection sites significantly predicted their seed oil melting points. In addition, a genome-wide association study (GWAS) was performed to determine which genes were most likely responsible for the natural variation in seed oil melting point. The GWAS found a single highly significant association within the coding region of FAD2, which encodes a fatty acid desaturase central to the oil biosynthesis pathway. In a separate analysis of 15 a priori oil synthesis candidate genes, 2 (FAD2 and FATB) were located near significant SNPs associated with seed oil melting point. These results comport with others' molecular work showing that lines with alterations in these genes affect seed oil melting point as expected. Our results suggest natural selection has acted on a small number of loci to alter a quantitative trait in response to local environmental conditions.
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Affiliation(s)
- Sandra E Branham
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX (Branham, Reba, and Linder); and Division of Plant Sciences, University of Missouri, Columbia, MO (Morrison).
| | - Sara J Wright
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX (Branham, Reba, and Linder); and Division of Plant Sciences, University of Missouri, Columbia, MO (Morrison)
| | - Aaron Reba
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX (Branham, Reba, and Linder); and Division of Plant Sciences, University of Missouri, Columbia, MO (Morrison)
| | - Ginnie D Morrison
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX (Branham, Reba, and Linder); and Division of Plant Sciences, University of Missouri, Columbia, MO (Morrison)
| | - C Randal Linder
- From the US Vegetable Laboratory, Agricultural Research Service, United States Department of Agriculture, Charleston, SC 29414 (Branham); Department of Biology, Washington University, St. Louis, MO (Wright); Integrative Biology Department, University of Texas at Austin, Austin, TX (Branham, Reba, and Linder); and Division of Plant Sciences, University of Missouri, Columbia, MO (Morrison)
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5
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Jasinski S, Lécureuil A, Durandet M, Bernard-Moulin P, Guerche P. Arabidopsis Seed Content QTL Mapping Using High-Throughput Phenotyping: The Assets of Near Infrared Spectroscopy. FRONTIERS IN PLANT SCIENCE 2016; 7:1682. [PMID: 27891138 PMCID: PMC5103166 DOI: 10.3389/fpls.2016.01682] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/25/2016] [Indexed: 05/04/2023]
Abstract
Seed storage compounds are of crucial importance for human diet, feed and industrial uses. In oleo-proteaginous species like rapeseed, seed oil and protein are the qualitative determinants that conferred economic value to the harvested seed. To date, although the biosynthesis pathways of oil and storage protein are rather well-known, the factors that determine how these types of reserves are partitioned in seeds have to be identified. With the aim of implementing a quantitative genetics approach, requiring phenotyping of 100s of plants, our first objective was to establish near-infrared reflectance spectroscopic (NIRS) predictive equations in order to estimate oil, protein, carbon, and nitrogen content in Arabidopsis seed with high-throughput level. Our results demonstrated that NIRS is a powerful non-destructive, high-throughput method to assess the content of these four major components studied in Arabidopsis seed. With this tool in hand, we analyzed Arabidopsis natural variation for these four components and illustrated that they all displayed a wide range of variation. Finally, NIRS was used in order to map QTL for these four traits using seeds from the Arabidopsis thaliana Ct-1 × Col-0 recombinant inbred line population. Some QTL co-localized with QTL previously identified, but others mapped to chromosomal regions never identified so far for such traits. This paper illustrates the usefulness of NIRS predictive equations to perform accurate high-throughput phenotyping of Arabidopsis seed content, opening new perspectives in gene identification following QTL mapping and genome wide association studies.
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Affiliation(s)
- Sophie Jasinski
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-SaclayVersailles, France
- *Correspondence: Sophie Jasinski,
| | - Alain Lécureuil
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-SaclayVersailles, France
| | - Monique Durandet
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-SaclayVersailles, France
| | | | - Philippe Guerche
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-SaclayVersailles, France
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Wang ML, Khera P, Pandey MK, Wang H, Qiao L, Feng S, Tonnis B, Barkley NA, Pinnow D, Holbrook CC, Culbreath AK, Varshney RK, Guo B. Genetic mapping of QTLs controlling fatty acids provided insights into the genetic control of fatty acid synthesis pathway in peanut (Arachis hypogaea L.). PLoS One 2015; 10:e0119454. [PMID: 25849082 PMCID: PMC4388682 DOI: 10.1371/journal.pone.0119454] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 01/19/2015] [Indexed: 01/12/2023] Open
Abstract
Peanut, a high-oil crop with about 50% oil content, is either crushed for oil or used as edible products. Fatty acid composition determines the oil quality which has high relevance to consumer health, flavor, and shelf life of commercial products. In addition to the major fatty acids, oleic acid (C18:1) and linoleic acid (C18:2) accounting for about 80% of peanut oil, the six other fatty acids namely palmitic acid (C16:0), stearic acid (C18:0), arachidic acid (C20:0), gadoleic acid (C20:1), behenic acid (C22:0), and lignoceric acid (C24:0) are accounted for the rest 20%. To determine the genetic basis and to improve further understanding on effect of FAD2 genes on these fatty acids, two recombinant inbred line (RIL) populations namely S-population (high oleic line 'SunOleic 97R' × low oleic line 'NC94022') and T-population (normal oleic line 'Tifrunner' × low oleic line 'GT-C20') were developed. Genetic maps with 206 and 378 marker loci for the S- and the T-population, respectively were used for quantitative trait locus (QTL) analysis. As a result, a total of 164 main-effect (M-QTLs) and 27 epistatic (E-QTLs) QTLs associated with the minor fatty acids were identified with 0.16% to 40.56% phenotypic variation explained (PVE). Thirty four major QTLs (>10% of PVE) mapped on five linkage groups and 28 clusters containing more than three QTLs were also identified. These results suggest that the major QTLs with large additive effects would play an important role in controlling composition of these minor fatty acids in addition to the oleic and linoleic acids in peanut oil. The interrelationship among these fatty acids should be considered while breeding for improved peanut genotypes with good oil quality and desired fatty acid composition.
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Affiliation(s)
- Ming Li Wang
- Plant Genetics Resources Conservation Unit, US Department of Agriculture-Agricultural Research Service, Griffin, Georgia, United States of America
| | - Pawan Khera
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, India
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
| | - Manish K. Pandey
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, India
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
| | - Hui Wang
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
- Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Lixian Qiao
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
- College of Life Science, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Suping Feng
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
- College of Bioscience and Biotechnology, Qiongzhou University, Sanya, Hainan, China
| | - Brandon Tonnis
- Plant Genetics Resources Conservation Unit, US Department of Agriculture-Agricultural Research Service, Griffin, Georgia, United States of America
| | - Noelle A. Barkley
- Plant Genetics Resources Conservation Unit, US Department of Agriculture-Agricultural Research Service, Griffin, Georgia, United States of America
| | - David Pinnow
- Plant Genetics Resources Conservation Unit, US Department of Agriculture-Agricultural Research Service, Griffin, Georgia, United States of America
| | - Corley C. Holbrook
- Crop Genetics and Breeding Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
| | - Albert K. Culbreath
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
| | - Rajeev K. Varshney
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, India
| | - Baozhu Guo
- Crop Protection and Management Research Unit, US Department of Agriculture-Agricultural Research Service, Tifton, Georgia, United States of America
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
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Pelc SE, Linder CR. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana. Ecol Evol 2015; 5:164-71. [PMID: 25628873 PMCID: PMC4298443 DOI: 10.1002/ece3.1265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 11/18/2022] Open
Abstract
Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high- and low-melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high-melting point lines had lower fitness relative to those against low-melting point lines, which matched expectations for undifferentiated emergence times.
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Affiliation(s)
- Sandra E Pelc
- US Vegetable Laboratory, Agricultural Research Service, United States Department of AgricultureCharleston, South Carolina, 29414
- Department of Integrative Biology, University of Texas at AustinAustin, Texas, 78712
| | - C Randal Linder
- Department of Integrative Biology, University of Texas at AustinAustin, Texas, 78712
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Lz-0 × Berkeley: a new Arabidopsis recombinant inbred line population for the mapping of complex traits. Mol Genet Genomics 2014; 289:417-25. [PMID: 24532030 DOI: 10.1007/s00438-014-0820-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/25/2014] [Indexed: 10/25/2022]
Abstract
This study describes the generation and test of a genetic resource suited to identify determinants of cell biological traits in plants. The use of quantitative trait loci (QTL) mapping for a better genetic understanding of cell biological traits is still at an early stage, even for biotechnologically important cell properties, such as the dimensions of fiber cells. A common strategy, the mapping of QTLs in recombinant inbred line (RIL) populations, is limited by the fact that the existing RIL populations exploit only a small fraction of the existing natural variation. Here, we report the mapping of QTLs impacting on the length of fiber cells in Arabidopsis inflorescence stems in a newly generated RIL population derived from a cross between the accessions Berkeley and the little known Lz-0. Through inbreeding of individual F(2) plants, a total of 159 new F8 lines were produced and genotyped with a set of 49 single nucleotide polymorphism markers. The population was successfully used not only for the mapping of three QTLs controlling fiber length, but also to map five QTL controlling flowering time under short and long-day conditions. Our study demonstrates the usefulness of this new genetic resource by mapping in it QTLs underlying a poorly explored cellular trait as well as an already better explored regulatory pathway. The new RIL population and an online platform for the continuous supplementation of genetic markers will be generally available to substantially broaden the genetic diversity through which loci with impact on plant quantitative traits can be identified.
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9
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Sanyal A, Linder CR. Plasticity and constraints on fatty acid composition in the phospholipids and triacylglycerols of Arabidopsis accessions grown at different temperatures. BMC PLANT BIOLOGY 2013; 13:63. [PMID: 23594395 PMCID: PMC3637579 DOI: 10.1186/1471-2229-13-63] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 03/18/2013] [Indexed: 05/10/2023]
Abstract
BACKGROUND Natural selection acts on multiple traits in an organism, and the final outcome of adaptive evolution may be constrained by the interaction of physiological and functional integration of those traits. Fatty acid composition is an important determinant of seed oil quality. In plants the relative proportions of unsaturated fatty acids in phospholipids and seed triacylglycerols often increases adaptively in response to lower growing temperatures to increase fitness. Previous work produced evidence of genetic constraints between phospholipids and triacylglycerols in the widely studied Arabidopsis lines Col and Ler, but because these lines are highly inbred, the correlations might be spurious. In this study, we grew 84 wild Arabidopsis accessions at two temperatures to show that genetic correlation between the fatty acids of the two lipid types is not expected and one should not influence the other and seed oil evolution and also tested for the adaptive response of fatty acids to latitude and temperature. RESULTS As expected no significant correlations between the two lipids classes at either growing temperature were observed. The saturated fatty acids and erucic acid of triacylglycerols followed a significant latitudinal cline, while the fatty acids in phospholipids did not respond to latitude as expected. The expected plastic response to temperature was observed for all the triacylglycerol fatty acids whereas only oleic acid showed the expected pattern in phospholipids. Considerable phenotypic variation of the fatty acids in both the lipid types was seen. CONCLUSION We report the first evidence supporting adaptive evolution of seed triacylglycerols in Arabidopsis on a latitudinal cline as seen in other species and also their plastic adaptive response to growing temperature. We show that as expected there is no genetic correlations between the fatty acids in triacylglycerols and phospholipids, indicating selection can act on seed triacylglycerols without being constrained by the fatty acid requirements of the phospholipids. Phospholipid fatty acids do not respond to latitude and temperature as seen elsewhere and needs further investigation. Thus, the adaptive response of Arabidopsis and the genetic tools available for manipulating Arabidopsis, makes it an excellent system for studying seed oil evolution and also for breeding seed oil crops especially the Brassica species.
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Affiliation(s)
- Anushree Sanyal
- Section of Integrative Biology, School of Biological Sciences, University of Texas at Austin, Austin, TX, 78712, USA
- Department of Agronomy, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Craig Randal Linder
- Section of Integrative Biology, School of Biological Sciences, University of Texas at Austin, Austin, TX, 78712, USA
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10
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Capron A, Chang XF, Hall H, Ellis B, Beatson RP, Berleth T. Identification of quantitative trait loci controlling fibre length and lignin content in Arabidopsis thaliana stems. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:185-97. [PMID: 23136168 PMCID: PMC3528028 DOI: 10.1093/jxb/ers319] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Fibre properties and the biochemical composition of cell walls are important traits in many applications. For example, the lengths of fibres define the strength and quality of paper, and lignin content is a critical parameter for the use of biomass in biofuel production. Identifying genes controlling these traits is comparatively difficult in woody species, because of long generation times and limited amenability to high-resolution genetic mapping. To address this problem, this study mapped quantitative trait loci (QTLs) defining fibre length and lignin content in the Arabidopsis recombinant inbred line population Col-4 × Ler-0. Adapting high-throughput phenotyping techniques for both traits for measurements in Arabidopsis inflorescence stems identified significant QTLs for fibre length on chromosomes 2 and 5, as well as one significant QTL affecting lignin content on chromosome 2. For fibre length, total variation within the population was 208% higher than between parental lines and the identified QTLs explained 50.58% of the observed variation. For lignin content, the values were 261 and 26.51%, respectively. Bioinformatics analysis of the associated intervals identified a number of candidate genes for fibre length and lignin content. This study demonstrates that molecular mapping of QTLs pertaining to wood and fibre properties is possible in Arabidopsis, which substantially broadens the use of Arabidopsis as a model species for the functional characterization of plant genes.
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Affiliation(s)
- Arnaud Capron
- University of Toronto-CSB, 25 Willcocks Street, Toronto, ON, Canada, M5S 3B2
| | - Xue Feng Chang
- British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, BC, Canada, V5G 3H2
| | - Hardy Hall
- University of British Columbia – Michael Smith Laboratories, #301–2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Brian Ellis
- University of British Columbia – Michael Smith Laboratories, #301–2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Rodger P. Beatson
- British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, BC, Canada, V5G 3H2
| | - Thomas Berleth
- University of Toronto-CSB, 25 Willcocks Street, Toronto, ON, Canada, M5S 3B2
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