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Thomas J, Frugoli J. Mutation of BAM2 rescues the sunn hypernodulation phenotype in Medicago truncatula, suggesting that a signaling pathway like CLV1/BAM in Arabidopsis affects nodule number. FRONTIERS IN PLANT SCIENCE 2024; 14:1334190. [PMID: 38273950 PMCID: PMC10808729 DOI: 10.3389/fpls.2023.1334190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
The unique evolutionary adaptation of legumes for nitrogen-fixing symbiosis leading to nodulation is tightly regulated by the host plant. The autoregulation of nodulation (AON) pathway negatively regulates the number of nodules formed in response to the carbon/nitrogen metabolic status of the shoot and root by long-distance signaling to and from the shoot and root. Central to AON signaling in the shoots of Medicago truncatula is SUNN, a leucine-rich repeat receptor-like kinase with high sequence similarity with CLAVATA1 (CLV1), part of a class of receptors in Arabidopsis involved in regulating stem cell populations in the root and shoot. This class of receptors in Arabidopsis includes the BARELY ANY MERISTEM family, which, like CLV1, binds to CLE peptides and interacts with CLV1 to regulate meristem development. M. truncatula contains five members of the BAM family, but only MtBAM1 and MtBAM2 are highly expressed in the nodules 48 hours after inoculation. Plants carry mutations in individual MtBAMs, and several double BAM mutant combinations all displayed wild-type nodule number phenotypes. However, Mtbam2 suppressed the sunn-5 hypernodulation phenotype and partially rescued the short root length phenotype of sunn-5 when present in a sunn-5 background. Grafting determined that bam2 suppresses supernodulation from the roots, regardless of the SUNN status of the root. Overexpression of MtBAM2 in wild-type plants increases nodule numbers, while overexpression of MtBAM2 in some sunn mutants rescues the hypernodulation phenotype, but not the hypernodulation phenotypes of AON mutant rdn1-2 or crn. Relative expression measurements of the nodule transcription factor MtWOX5 downstream of the putative bam2 sunn-5 complex revealed disruption of meristem signaling; while both bam2 and bam2 sunn-5 influence MtWOX5 expression, the expression changes are in different directions. We propose a genetic model wherein the specific root interactions of BAM2/SUNN are critical for signaling in nodule meristem cell homeostasis in M. truncatula.
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Affiliation(s)
| | - Julia Frugoli
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, United States
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2
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Watts-Williams SJ, Wege S, Ramesh SA, Berkowitz O, Xu B, Gilliham M, Whelan J, Tyerman SD. The function of the Medicago truncatula ZIP transporter MtZIP14 is linked to arbuscular mycorrhizal fungal colonization. PLANT, CELL & ENVIRONMENT 2023; 46:1691-1704. [PMID: 36654510 DOI: 10.1111/pce.14545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/09/2023] [Accepted: 01/17/2023] [Indexed: 06/17/2023]
Abstract
Soil micronutrient availability, including zinc (Zn), is a limiting factor for crop yield. Arbuscular mycorrhizal (AM) fungi can improve host plant growth and nutrition through the mycorrhizal pathway of nutrient uptake. Although the physiology of Zn uptake through the mycorrhizal pathway is well established, the identity of the related molecular components are unknown. Here, RNA-seq analysis was used to identify genes differentially-regulated by AM colonization and soil Zn concentration in roots of Medicago truncatula. The putative Zn transporter gene MtZIP14 was markedly up-regulated in M. truncatula roots when colonized by Rhizophagus irregularis. MtZIP14 restored yeast growth under low Zn availability. Loss-of-function mutant plants (mtzip14) had reduced shoot biomass compared to the wild-type when colonized by AM fungi and grown under low and sufficient soil Zn concentration; at high soil Zn concentration, there were no genotypic differences in shoot biomass. The vesicular and arbuscular colonization of roots was lower in the mtzip14 plants regardless of soil Zn concentration. We propose that MtZIP14 is linked to AM colonization in M. truncatula plants, with the possibility that MtZIP14 function with AM colonization is linked to plant Zn nutrition.
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Affiliation(s)
- Stephanie J Watts-Williams
- The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia, Australia
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
| | - Stefanie Wege
- The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia, Australia
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
| | - Sunita A Ramesh
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Oliver Berkowitz
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
- Department of Animal Plant and Soil Science, School of Life Science, La Trobe University, Bundoora, Victoria, Australia
| | - Bo Xu
- The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia, Australia
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
| | - Matthew Gilliham
- The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia, Australia
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
| | - James Whelan
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
| | - Stephen D Tyerman
- The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia, Australia
- The Australian Research Council Centre of Excellence in Plant Energy Biology, Australia
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Cheng X, Xie H, Zhang K, Wen J. Enabling Medicago truncatula forward genetics: identification of genetic crossing partner for R108 and development of mapping resources for Tnt1 mutants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:608-616. [PMID: 35510429 DOI: 10.1111/tpj.15797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/19/2022] [Accepted: 05/01/2022] [Indexed: 06/14/2023]
Abstract
Though Medicago truncatula Tnt1 mutants are widely used by researchers in the legume community, they are mainly used for reverse genetics because of the availability of the BLAST-searchable large-scale flanking sequence tags database. However, these mutants should have also been used extensively for forward genetic screens, an effort that has been hindered due to the lack of a compatible genetic crossing partner for the M. truncatula genotype R108, from which Tnt1 mutants were generated. In this study, we selected three Medicago HapMap lines (HM017, HM018 and HM022) and performed reciprocal genetic crosses with R108. After phenotypic analyses in F1 and F2 progenies, HM017 was identified as a compatible crossing partner with R108. By comparing the assembled genomic sequences of HM017 and R108, we developed and confirmed 318 Indel markers evenly distributed across the eight chromosomes of the M. truncatula genome. To validate the effectiveness of these markers, by employing the map-based cloning approach, we cloned the causative gene in the dwarf mutant crs isolated from the Tnt1 mutant population, identifying it as gibberellin 3-β-dioxygenase 1, using some of the confirmed Indel markers. The primer sequences and the size difference of each marker were made available for users in the web-based database. The identification of the crossing partner for R108 and the generation of Indel markers will enhance the forward genetics and the overall usage of the Tnt1 mutants.
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Affiliation(s)
- Xiaofei Cheng
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Hongli Xie
- Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, 266109, China
| | - Kuihua Zhang
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Jiangqi Wen
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA
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Achom M, Roy P, Lagunas B, Picot E, Richards L, Bonyadi-Pour R, Pardal AJ, Baxter L, Richmond BL, Aschauer N, Fletcher EM, Rowson M, Blackwell J, Rich-Griffin C, Mysore KS, Wen J, Ott S, Carré IA, Gifford ML. Plant circadian clock control of Medicago truncatula nodulation via regulation of nodule cysteine-rich peptides. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2142-2156. [PMID: 34850882 PMCID: PMC8982390 DOI: 10.1093/jxb/erab526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
Legumes house nitrogen-fixing endosymbiotic rhizobia in specialized polyploid cells within root nodules, which undergo tightly regulated metabolic activity. By carrying out expression analysis of transcripts over time in Medicago truncatula nodules, we found that the circadian clock enables coordinated control of metabolic and regulatory processes linked to nitrogen fixation. This involves the circadian clock-associated transcription factor LATE ELONGATED HYPOCOTYL (LHY), with lhy mutants being affected in nodulation. Rhythmic transcripts in root nodules include a subset of nodule-specific cysteine-rich peptides (NCRs) that have the LHY-bound conserved evening element in their promoters. Until now, studies have suggested that NCRs act to regulate bacteroid differentiation and keep the rhizobial population in check. However, these conclusions came from the study of a few members of this very large gene family that has complex diversified spatio-temporal expression. We suggest that rhythmic expression of NCRs may be important for temporal coordination of bacterial activity with the rhythms of the plant host, in order to ensure optimal symbiosis.
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Affiliation(s)
- Mingkee Achom
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Proyash Roy
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
- Department of Genetic Engineering & Biotechnology, University of Dhaka, Dhaka, Bangladesh
| | - Beatriz Lagunas
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Emma Picot
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Luke Richards
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Roxanna Bonyadi-Pour
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Alonso J Pardal
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Laura Baxter
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Bethany L Richmond
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Nadine Aschauer
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Eleanor M Fletcher
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Monique Rowson
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Joseph Blackwell
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Charlotte Rich-Griffin
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kirankumar S Mysore
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK 73401, USA
| | - Jiangqi Wen
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK 73401, USA
| | - Sascha Ott
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Isabelle A Carré
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
| | - Miriam L Gifford
- School of Life Sciences, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, UK
- Warwick Integrative Synthetic Biology Centre, University of Warwick, Coventry CV4 7AL, UK
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5
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Li A, Liu A, Wu S, Qu K, Hu H, Yang J, Shrestha N, Liu J, Ren G. Comparison of structural variants in the whole genome sequences of two Medicago truncatula ecotypes: Jemalong A17 and R108. BMC PLANT BIOLOGY 2022; 22:77. [PMID: 35193491 PMCID: PMC8862580 DOI: 10.1186/s12870-022-03469-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Structural variants (SVs) constitute a large proportion of the genomic variation that results in phenotypic variation in plants. However, they are still a largely unexplored feature in most plant genomes. Here, we present the whole-genome landscape of SVs between two model legume Medicago truncatula ecotypes-Jemalong A17 and R108- that have been extensively used in various legume biology studies. RESULTS To catalogue SVs, we first resolved the previously published R108 genome assembly (R108 v1.0) to chromosome-scale using 124 × Hi-C data, resulting in a high-quality genome assembly. The inter-chromosomal reciprocal translocations between chromosomes 4 and 8 were confirmed by performing syntenic analysis between the two genomes. Combined with the Hi-C data, it appears that these translocation events had a significant effect on chromatin organization. Using both whole-genome and short-read alignments, we identified the genomic landscape of SVs between the two genomes, some of which may account for several phenotypic differences, including their differential responses to aluminum toxicity and iron deficiency, and the development of different anthocyanin leaf markings. We also found extensive SVs within the nodule-specific cysteine-rich gene family which encodes antimicrobial peptides essential for terminal bacteroid differentiation during nitrogen-fixing symbiosis. CONCLUSIONS Our results provide a near-complete R108 genome assembly and the first genomic landscape of SVs obtained by comparing two M. truncatula ecotypes. This may provide valuable genomic resources for the functional and molecular research of legume biology in the future.
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Affiliation(s)
- Ao Li
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Ai Liu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Shuang Wu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Kunjing Qu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Hongyin Hu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Jinli Yang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Nawal Shrestha
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Jianquan Liu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education & State Key Lab of Hydraulics and Mountain River Engineering, College of Life Sciences, Sichuan University, Chengdu, China
| | - Guangpeng Ren
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, China.
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Coulibaly M, Bodjrenou G, Akohoue F, Agoyi EE, Merinosy Francisco FM, Agossou COA, Sawadogo M, Achigan-Dako EG. Profiling Cultivars Development in Kersting's Groundnut [Macrotyloma geocarpum (Harms) Maréchal and Baudet] for Improved Yield, Higher Nutrient Content, and Adaptation to Current and Future Climates. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2021.759575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Kersting's groundnut [Macrotyloma geocarpum (Harms.) Maréchal and Baudet], Fabaceae, is an important source of protein and essential amino acids. As a grain legume species, it also contributes to improving soil fertility through symbiotic nitrogen fixation. However, the crop is characterized by a relatively low yield (≤500 kg/ha), and limited progress has been made so far, toward the development of high-yielding cultivars that can enhance and sustain its productivity. Recently, there was an increased interest in alleviating the burdens related to Kersting's groundnut (KG) cultivation through the development of improved varieties. Preliminary investigations assembled germplasms from various producing countries. In-depth ethnobotanical studies and insightful investigation on the reproductive biology of the species were undertaken alongside morphological, biochemical, and molecular characterizations. Those studies revealed a narrow genetic base for KG. In addition, the self-pollinating nature of its flowers prevents cross-hybridization and represents a major barrier limiting the broadening of the genetic basis. Therefore, the development of a research pipeline to address the bottlenecks specific to KG is a prerequisite for the successful expansion of the crop. In this paper, we offer an overview of the current state of research on KG and pinpoint the knowledge gaps; we defined and discussed the main steps of breeding for KG' cultivars development; this included (i) developing an integrated genebank, inclusive germplasm, and seed system management; (ii) assessing end-users preferences and possibility for industrial exploitation of the crop; (iii) identifying biotic and abiotic stressors and the genetic control of responsive traits to those factors; (iv) overcoming the cross-pollination challenges in KG to propel the development of hybrids; (v) developing new approaches to create variability and setting adequate cultivars and breeding approaches; (vi) karyotyping and draft genome analysis to accelerate cultivars development and increase genetic gains; and (vii) evaluating the adaptability and stability of cultivars across various ecological regions.
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Zhang L, Kamphuis LG, Guo Y, Jacques S, Singh KB, Gao LL. Ethylene Is Not Essential for R-Gene Mediated Resistance but Negatively Regulates Moderate Resistance to Some Aphids in Medicago truncatula. Int J Mol Sci 2020; 21:ijms21134657. [PMID: 32629952 PMCID: PMC7369913 DOI: 10.3390/ijms21134657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/23/2020] [Accepted: 06/27/2020] [Indexed: 02/02/2023] Open
Abstract
Ethylene is important for plant responses to environmental factors. However, little is known about its role in aphid resistance. Several types of genetic resistance against multiple aphid species, including both moderate and strong resistance mediated by R genes, have been identified in Medicago truncatula. To investigate the potential role of ethylene, a M. truncatula ethylene- insensitive mutant, sickle, was analysed. The sickle mutant occurs in the accession A17 that has moderate resistance to Acyrthosiphon kondoi, A. pisum and Therioaphis trifolii. The sickle mutant resulted in increased antibiosis-mediated resistance against A. kondoi and T. trifolii but had no effect on A. pisum. When sickle was introduced into a genetic background carrying resistance genes, AKR (A. kondoi resistance), APR (A. pisum resistance) and TTR (T. trifolii resistance), it had no effect on the strong aphid resistance mediated by these genes, suggesting that ethylene signaling is not essential for their function. Interestingly, for the moderate aphid resistant accession, the sickle mutant delayed leaf senescence following aphid infestation and reduced the plant biomass losses caused by both A. kondoi and T. trifolii. These results suggest manipulation of the ethylene signaling pathway could provide aphid resistance and enhance plant tolerance against aphid feeding.
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Affiliation(s)
- Lijun Zhang
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- College of Plant Protection, Shanxi Agricultural University, Taigu 030801, China
| | - Lars G. Kamphuis
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- The UWA Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
| | - Yanqiong Guo
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- College of Plant Protection, Shanxi Agricultural University, Taigu 030801, China
| | - Silke Jacques
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- College of Plant Protection, Shanxi Agricultural University, Taigu 030801, China
| | - Karam B. Singh
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- The UWA Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
- Correspondence: (K.B.S.); (L.-L.G.); Tel.:+61-8-9333-6320 (K.B.S.); Fax: +61-8-9387-8991 (K.B.S.)
| | - Ling-Ling Gao
- CSIRO Agriculture and Food, Wembley, WA 6014, Australia; (L.Z.); (L.G.K.); (Y.G.); (S.J.)
- Correspondence: (K.B.S.); (L.-L.G.); Tel.:+61-8-9333-6320 (K.B.S.); Fax: +61-8-9387-8991 (K.B.S.)
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8
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Kalinger RS, Pulsifer IP, Rowland O. Elucidating the substrate specificities of acyl-lipid thioesterases from diverse plant taxa. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 127:104-118. [PMID: 29571003 DOI: 10.1016/j.plaphy.2018.03.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 05/21/2023]
Abstract
Acyl-ACP thioesterase enzymes, which cleave fatty acyl thioester bonds to release free fatty acids, contribute to much of the fatty acid diversity in plants. In Arabidopsis thaliana, a family of four single hot-dog fold domain, plastid-localized acyl-lipid thioesterases (AtALT1-4) generate medium-chain (C6-C14) fatty and β-keto fatty acids as secondary metabolites. These volatile products may serve to attract insect pollinators or deter predatory insects. Homologs of AtALT1-4 are present in all plant taxa, but are nearly all uncharacterized. Despite high sequence identity, AtALT1-4 generate different lipid products, suggesting that ALT homologs in other plants also have highly varied activities. We investigated the catalytic diversity of ALT-like thioesterases by screening the substrate specificities of 15 ALT homologs from monocots, eudicots, a lycophyte, a green microalga, and the ancient gymnosperm Gingko biloba, via expression in Escherichia coli. Overall, these enzymes had highly varied substrate preferences compared to one another and to AtALT1-4, and could be classified into four catalytic groups comprising members from diverse taxa. Group 1 ALTs primarily generated 14:1 β-keto fatty acids, Group 2 ALTs produced 6-10 carbon fatty/β-keto fatty acids, Group 3 ALTs predominantly produced 12-14 carbon fatty acids, and Group 4 ALTs mainly generated 16 carbon fatty acids. Enzymes in each group differed significantly in the quantities of lipids and types of minor products they generated in E. coli. Medium-chain fatty acids are used to manufacture insecticides, pharmaceuticals, and biofuels, and ALT-like proteins are ideal candidates for metabolic engineering to produce specific fatty acids in significant quantities.
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Affiliation(s)
- Rebecca S Kalinger
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Ian P Pulsifer
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Owen Rowland
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
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9
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Kryvoruchko IS, Routray P, Sinharoy S, Torres-Jerez I, Tejada-Jiménez M, Finney LA, Nakashima J, Pislariu CI, Benedito VA, González-Guerrero M, Roberts DM, Udvardi MK. An Iron-Activated Citrate Transporter, MtMATE67, Is Required for Symbiotic Nitrogen Fixation. PLANT PHYSIOLOGY 2018; 176:2315-2329. [PMID: 29284744 PMCID: PMC5841734 DOI: 10.1104/pp.17.01538] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/21/2017] [Indexed: 05/23/2023]
Abstract
Iron (Fe) is an essential micronutrient for symbiotic nitrogen fixation in legume nodules, where it is required for the activity of bacterial nitrogenase, plant leghemoglobin, respiratory oxidases, and other Fe proteins in both organisms. Fe solubility and transport within and between plant tissues is facilitated by organic chelators, such as nicotianamine and citrate. We have characterized a nodule-specific citrate transporter of the multidrug and toxic compound extrusion family, MtMATE67 of Medicago truncatula The MtMATE67 gene was induced early during nodule development and expressed primarily in the invasion zone of mature nodules. The MtMATE67 protein was localized to the plasma membrane of nodule cells and also the symbiosome membrane surrounding bacteroids in infected cells. In oocytes, MtMATE67 transported citrate out of cells in an Fe-activated manner. Loss of MtMATE67 gene function resulted in accumulation of Fe in the apoplasm of nodule cells and a substantial decrease in symbiotic nitrogen fixation and plant growth. Taken together, the results point to a primary role of MtMATE67 in citrate efflux from nodule cells in response to an Fe signal. This efflux is necessary to ensure Fe(III) solubility and mobility in the apoplasm and uptake into nodule cells. Likewise, MtMATE67-mediated citrate transport into the symbiosome space would increase the solubility and availability of Fe(III) for rhizobial bacteroids.
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Affiliation(s)
| | - Pratyush Routray
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | | | | | - Manuel Tejada-Jiménez
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Universidad Politécnica de Madrid, Madrid 28223, Spain
| | | | | | | | - Vagner A Benedito
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, West Virginia 26506
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Universidad Politécnica de Madrid, Madrid 28223, Spain
| | - Daniel M Roberts
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
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10
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Garmier M, Gentzbittel L, Wen J, Mysore KS, Ratet P. Medicago truncatula: Genetic and Genomic Resources. ACTA ACUST UNITED AC 2017; 2:318-349. [PMID: 33383982 DOI: 10.1002/cppb.20058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Medicago truncatula was chosen by the legume community, along with Lotus japonicus, as a model plant to study legume biology. Since then, numerous resources and tools have been developed for M. truncatula. These include, for example, its genome sequence, core ecotype collections, transformation/regeneration methods, extensive mutant collections, and a gene expression atlas. This review aims to describe the different genetic and genomic tools and resources currently available for M. truncatula. We also describe how these resources were generated and provide all the information necessary to access these resources and use them from a practical point of view. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Marie Garmier
- Institute of Plant Sciences Paris-Saclay, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique, Université Paris-Sud, Université Evry, Université Paris-Saclay, Orsay, France.,Institute of Plant Sciences Paris-Saclay, Université Paris Diderot, Université Sorbonne Paris-Cité, Orsay, France
| | - Laurent Gentzbittel
- EcoLab, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National Polytechnique de Toulouse, Université Paul Sabatier, Castanet-Tolosan, France
| | | | | | - Pascal Ratet
- Institute of Plant Sciences Paris-Saclay, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique, Université Paris-Sud, Université Evry, Université Paris-Saclay, Orsay, France.,Institute of Plant Sciences Paris-Saclay, Université Paris Diderot, Université Sorbonne Paris-Cité, Orsay, France
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Codon usage and amino acid usage influence genes expression level. Genetica 2017; 146:53-63. [DOI: 10.1007/s10709-017-9996-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 10/09/2017] [Indexed: 11/30/2022]
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Veerappan V, Jani M, Kadel K, Troiani T, Gale R, Mayes T, Shulaev E, Wen J, Mysore KS, Azad RK, Dickstein R. Rapid identification of causative insertions underlying Medicago truncatula Tnt1 mutants defective in symbiotic nitrogen fixation from a forward genetic screen by whole genome sequencing. BMC Genomics 2016; 17:141. [PMID: 26920390 PMCID: PMC4769575 DOI: 10.1186/s12864-016-2452-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/09/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND In the model legume Medicago truncatula, the near saturation genome-wide Tnt1 insertion mutant population in ecotype R108 is a valuable tool in functional genomics studies. Forward genetic screens have identified many Tnt1 mutants defective in nodule development and symbiotic nitrogen fixation (SNF). However, progress toward identifying the causative mutations of these symbiotic mutants has been slow because of the high copy number of Tnt1 insertions in some mutant plants and inefficient recovery of flanking sequence tags (FSTs) by thermal asymmetric interlaced PCR (TAIL-PCR) and other techniques. RESULTS Two Tnt1 symbiotic mutants, NF11217 and NF10547, with defects in nodulation and SNF were isolated during a forward genetic screen. Both TAIL-PCR and whole genome sequencing (WGS) approaches were used in attempts to find the relevant mutant genes in NF11217 and NF10547. Illumina paired-end WGS generated ~16 Gb of sequence data from a 500 bp insert library for each mutant, yielding ~40X genome coverage. Bioinformatics analysis of the sequence data identified 97 and 65 high confidence independent Tnt1 insertion loci in NF11217 and NF10547, respectively. In comparison to TAIL-PCR, WGS recovered more Tnt1 insertions. From the WGS data, we found Tnt1 insertions in the exons of the previously described PHOSPHOLIPASE C (PLC)-like and NODULE INCEPTION (NIN) genes in NF11217 and NF10547 mutants, respectively. Co-segregation analyses confirmed that the symbiotic phenotypes of NF11217 and NF10547 are tightly linked to the Tnt1 insertions in PLC-like and NIN genes, respectively. CONCLUSIONS In this work, we demonstrate that WGS is an efficient approach for identification of causative genes underlying SNF defective phenotypes in M. truncatula Tnt1 insertion mutants obtained via forward genetic screens.
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Affiliation(s)
- Vijaykumar Veerappan
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Mehul Jani
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Khem Kadel
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Taylor Troiani
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Ronny Gale
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Tyler Mayes
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Elena Shulaev
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Jiangqi Wen
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
| | - Kirankumar S Mysore
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
| | - Rajeev K Azad
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA. .,Department of Mathematics, University of North Texas, Denton, TX, 76203, USA.
| | - Rebecca Dickstein
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
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Veerappan V, Jani M, Kadel K, Troiani T, Gale R, Mayes T, Shulaev E, Wen J, Mysore KS, Azad RK, Dickstein R. Rapid identification of causative insertions underlying Medicago truncatula Tnt1 mutants defective in symbiotic nitrogen fixation from a forward genetic screen by whole genome sequencing. BMC Genomics 2016. [PMID: 26920390 DOI: 10.1186/s12864-12016-12452-12865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023] Open
Abstract
BACKGROUND In the model legume Medicago truncatula, the near saturation genome-wide Tnt1 insertion mutant population in ecotype R108 is a valuable tool in functional genomics studies. Forward genetic screens have identified many Tnt1 mutants defective in nodule development and symbiotic nitrogen fixation (SNF). However, progress toward identifying the causative mutations of these symbiotic mutants has been slow because of the high copy number of Tnt1 insertions in some mutant plants and inefficient recovery of flanking sequence tags (FSTs) by thermal asymmetric interlaced PCR (TAIL-PCR) and other techniques. RESULTS Two Tnt1 symbiotic mutants, NF11217 and NF10547, with defects in nodulation and SNF were isolated during a forward genetic screen. Both TAIL-PCR and whole genome sequencing (WGS) approaches were used in attempts to find the relevant mutant genes in NF11217 and NF10547. Illumina paired-end WGS generated ~16 Gb of sequence data from a 500 bp insert library for each mutant, yielding ~40X genome coverage. Bioinformatics analysis of the sequence data identified 97 and 65 high confidence independent Tnt1 insertion loci in NF11217 and NF10547, respectively. In comparison to TAIL-PCR, WGS recovered more Tnt1 insertions. From the WGS data, we found Tnt1 insertions in the exons of the previously described PHOSPHOLIPASE C (PLC)-like and NODULE INCEPTION (NIN) genes in NF11217 and NF10547 mutants, respectively. Co-segregation analyses confirmed that the symbiotic phenotypes of NF11217 and NF10547 are tightly linked to the Tnt1 insertions in PLC-like and NIN genes, respectively. CONCLUSIONS In this work, we demonstrate that WGS is an efficient approach for identification of causative genes underlying SNF defective phenotypes in M. truncatula Tnt1 insertion mutants obtained via forward genetic screens.
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Affiliation(s)
- Vijaykumar Veerappan
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Mehul Jani
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Khem Kadel
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Taylor Troiani
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Ronny Gale
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Tyler Mayes
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Elena Shulaev
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
| | - Jiangqi Wen
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
| | - Kirankumar S Mysore
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
| | - Rajeev K Azad
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA. .,Department of Mathematics, University of North Texas, Denton, TX, 76203, USA.
| | - Rebecca Dickstein
- Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203, USA.
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Stetter MG, Zeitler L, Steinhaus A, Kroener K, Biljecki M, Schmid KJ. Crossing Methods and Cultivation Conditions for Rapid Production of Segregating Populations in Three Grain Amaranth Species. FRONTIERS IN PLANT SCIENCE 2016; 7:816. [PMID: 27375666 PMCID: PMC4894896 DOI: 10.3389/fpls.2016.00816] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/25/2016] [Indexed: 05/18/2023]
Abstract
Grain amaranths (Amaranthus spp.) have been cultivated for thousands of years in Central and South America. Their grains are of high nutritional value, but the low yield needs to be increased by selection of superior genotypes from genetically diverse breeding populations. Amaranths are adapted to harsh conditions and can be cultivated on marginal lands although little is known about their physiology. The development of controlled growing conditions and efficient crossing methods is important for research on and improvement of this ancient crop. Grain amaranth was domesticated in the Americas and is highly self-fertilizing with a large inflorescence consisting of thousands of very small flowers. We evaluated three different crossing methods (open pollination, hot water emasculation and hand emasculation) for their efficiency in amaranth and validated them with genetic markers. We identified cultivation conditions that allow an easy control of flowering time by day length manipulation and achieved flowering times of 4 weeks and generation times of 2 months. All three different crossing methods successfully produced hybrid F1 offspring, but with different success rates. Open pollination had the lowest (10%) and hand emasculation the highest success rate (74%). Hot water emasculation showed an intermediate success rate (26%) with a maximum of 94% success. It is simple to perform and suitable for a more large-scale production of hybrids. We further evaluated 11 single nucleotide polymorphism (SNP) markers and found that they were sufficient to validate all crosses of the genotypes used in this study for intra- and interspecific hybridizations. Despite its very small flowers, crosses in amaranth can be carried out efficiently and evaluated with inexpensive SNP markers. Suitable growth conditions strongly reduce the generation time and allow the control of plant height, flowering time, and seed production. In combination, this enables the rapid production of segregating populations which makes amaranth an attractive model for basic plant research but also facilitates further the improvement of this ancient crop by plant breeding.
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