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Vega JM, Podio M, Orjuela J, Siena LA, Pessino SC, Combes MC, Mariac C, Albertini E, Pupilli F, Ortiz JPA, Leblanc O. Chromosome-scale genome assembly and annotation of Paspalum notatum Flüggé var. saurae. Sci Data 2024; 11:891. [PMID: 39152143 PMCID: PMC11329641 DOI: 10.1038/s41597-024-03731-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 08/02/2024] [Indexed: 08/19/2024] Open
Abstract
Paspalum notatum Flüggé is an economically important subtropical fodder grass that is widely used in the Americas. Here, we report a new chromosome-scale genome assembly and annotation of a diploid biotype collected in the center of origin of the species. Using Oxford Nanopore long reads, we generated a 557.81 Mb genome assembly (N50 = 56.1 Mb) with high gene completeness (BUSCO = 98.73%). Genome annotation identified 320 Mb (57.86%) of repetitive elements and 45,074 gene models, of which 36,079 have a high level of confidence. Further characterisation included the identification of 59 miRNA precursors together with their putative targets. The present work provides a comprehensive genomic resource for P. notatum improvement and a reference frame for functional and evolutionary research within the genus.
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Grants
- PUE 22920160100043CO Consejo Nacional de Investigaciones Científicas y Técnicas (National Scientific and Technical Research Council)
- PIP 11220200101680CO Consejo Nacional de Investigaciones Científicas y Técnicas (National Scientific and Technical Research Council)
- PICT 2019 3414 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT 2019-02153 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT-2017-1956 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PIP 80020190300021UR Universidad Nacional de Rosario (National University of Rosario)
- 101007438 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska-Curie Actions (H2020 Excellent Science - Marie Skłodowska-Curie Actions)
- 872417 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska-Curie Actions (H2020 Excellent Science - Marie Skłodowska-Curie Actions)
- PRIN 2022Z4HLLJ Ministero dell'Istruzione, dell'Università e della Ricerca (Ministry of Education, University and Research)
- P2022KFJB5 Ministero dell'Istruzione, dell'Università e della Ricerca (Ministry of Education, University and Research)
- Ministero dell'Istruzione, dell'Università e della Ricerca (Ministry of Education, University and Research)
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Affiliation(s)
- Juan Manuel Vega
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla (S2125ZAA), Santa Fe, Argentina
| | - Maricel Podio
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla (S2125ZAA), Santa Fe, Argentina
| | - Julie Orjuela
- DIADE, Univ. Montpellier, CIRAD, IRD, Montpellier, France
| | - Lorena A Siena
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla (S2125ZAA), Santa Fe, Argentina
| | - Silvina C Pessino
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla (S2125ZAA), Santa Fe, Argentina
| | | | - Cedric Mariac
- DIADE, Univ. Montpellier, CIRAD, IRD, Montpellier, France
| | - Emidio Albertini
- Department of Agricultural, Food and Environmental Science, University of Perugia, 06121, Perugia, Italy
| | - Fulvio Pupilli
- Institute of Biosciences and Bioresources (IBBR), National Research Council (CNR), 06128, Perugia, Italy
| | - Juan Pablo A Ortiz
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla (S2125ZAA), Santa Fe, Argentina.
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Siena LA, Michaud C, Selles B, Vega JM, Pessino SC, Ingouff M, Ortiz JPA, Leblanc O. TRIMETHYLGUANOSINE SYNTHASE1 mutations decanalize female germline development in Arabidopsis. THE NEW PHYTOLOGIST 2023; 240:597-612. [PMID: 37548040 DOI: 10.1111/nph.19179] [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: 03/17/2023] [Accepted: 07/14/2023] [Indexed: 08/08/2023]
Abstract
Here, we report the characterization of a plant RNA methyltransferase, orthologous to yeast trimethylguanosine synthase1 (Tgs1p) and whose downregulation was associated with apomixis in Paspalum grasses. Using phylogenetic analyses and yeast complementation, we determined that land plant genomes all encode a conserved, specific TGS1 protein. Next, we studied the role of TGS1 in female reproduction using reporter lines and loss-of-function mutants in Arabidopsis thaliana. pAtTGS1:AtTGS1 reporters showed a dynamic expression pattern. They were highly active in the placenta and ovule primordia at emergence but, subsequently, showed weak signals in the nucellus. Although expressed throughout gametophyte development, activity became restricted to the female gamete and was also detected after fertilization during embryogenesis. TGS1 depletion altered the specification of the precursor cells that give rise to the female gametophytic generation and to the sporophyte, resulting in the formation of a functional aposporous-like lineage. Our results indicate that TGS1 participates in the mechanisms restricting cell fate acquisition to a single cell at critical transitions throughout the female reproductive lineage and, thus, expand our current knowledge of the mechanisms governing female reproductive fate in plants.
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Affiliation(s)
- Lorena A Siena
- Instituto de Investigaciones en Ciencias Agrarias de Rosario, CONICET-Universidad Nacional de Rosario, S2125ZAA, Zavalla, Argentina
| | | | - Benjamin Selles
- DIADE, Univ Montpellier, IRD, CIRAD, 34394, Montpellier, France
| | - Juan Manuel Vega
- Instituto de Investigaciones en Ciencias Agrarias de Rosario, CONICET-Universidad Nacional de Rosario, S2125ZAA, Zavalla, Argentina
| | - Silvina C Pessino
- Instituto de Investigaciones en Ciencias Agrarias de Rosario, CONICET-Universidad Nacional de Rosario, S2125ZAA, Zavalla, Argentina
| | - Mathieu Ingouff
- DIADE, Univ Montpellier, IRD, CIRAD, 34394, Montpellier, France
| | - Juan Pablo A Ortiz
- Instituto de Investigaciones en Ciencias Agrarias de Rosario, CONICET-Universidad Nacional de Rosario, S2125ZAA, Zavalla, Argentina
| | - Olivier Leblanc
- DIADE, Univ Montpellier, IRD, CIRAD, 34394, Montpellier, France
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Ouedraogo I, Lartaud M, Baroux C, Mosca G, Delgado L, Leblanc O, Verdeil JL, Conéjéro G, Autran D. 3D cellular morphometrics of ovule primordium development in Zea mays reveal differential division and growth dynamics specifying megaspore mother cell singleness. FRONTIERS IN PLANT SCIENCE 2023; 14:1174171. [PMID: 37251753 PMCID: PMC10213557 DOI: 10.3389/fpls.2023.1174171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 04/07/2023] [Indexed: 05/31/2023]
Abstract
Introduction Differentiation of spore mother cells marks the somatic-to-reproductive transition in higher plants. Spore mother cells are critical for fitness because they differentiate into gametes, leading to fertilization and seed formation. The female spore mother cell is called the megaspore mother cell (MMC) and is specified in the ovule primordium. The number of MMCs varies by species and genetic background, but in most cases, only a single mature MMC enters meiosis to form the embryo sac. Multiple candidate MMC precursor cells have been identified in both rice and Arabidopsis, so variability in MMC number is likely due to conserved early morphogenetic events. In Arabidopsis, the restriction of a single MMC per ovule, or MMC singleness, is determined by ovule geometry. To look for potential conservation of MMC ontogeny and specification mechanisms, we undertook a morphogenetic description of ovule primordium growth at cellular resolution in the model crop maize. Methods We generated a collection of 48 three-dimensional (3D) ovule primordium images for five developmental stages, annotated for 11 cell types. Quantitative analysis of ovule and cell morphological descriptors allowed the reconstruction of a plausible developmental trajectory of the MMC and its neighbors. Results The MMC is specified within a niche of enlarged, homogenous L2 cells, forming a pool of candidate archesporial (MMC progenitor) cells. A prevalent periclinal division of the uppermost central archesporial cell formed the apical MMC and the underlying cell, a presumptive stack cell. The MMC stopped dividing and expanded, acquiring an anisotropic, trapezoidal shape. By contrast, periclinal divisions continued in L2 neighbor cells, resulting in a single central MMC. Discussion We propose a model where anisotropic ovule growth in maize drives L2 divisions and MMC elongation, coupling ovule geometry with MMC fate.
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Affiliation(s)
- Inès Ouedraogo
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
| | - Marc Lartaud
- AGAP, University of Montpellier, CIRAD, INRAE, Institut SupAgro, Montpellier, France
| | - Célia Baroux
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Gabriella Mosca
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | | | - Oliver Leblanc
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
| | - Jean-Luc Verdeil
- AGAP, University of Montpellier, CIRAD, INRAE, Institut SupAgro, Montpellier, France
| | - Geneviève Conéjéro
- IPSIM, University of Montpellier, CNRS, INRAE, Institut SupAgro, Montpellier, France
| | - Daphné Autran
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
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Ferraz R, Coimbra S, Correia S, Canhoto J. RNA methyltransferases in plants: Breakthroughs in function and evolution. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 194:449-460. [PMID: 36502609 DOI: 10.1016/j.plaphy.2022.12.001] [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: 09/08/2022] [Revised: 11/28/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Each day it is becoming increasingly difficult not to notice the completely new, fast growing, extremely intricate and challenging world of epitranscriptomics as the understanding of RNA methylation is expanding at a hasty rate. Writers (methyltransferases), erasers (demethylases) and readers (RNA-binding proteins) are responsible for adding, removing and recognising methyl groups on RNA, respectively. Several methyltransferases identified in plants are now being investigated and recent studies have shown a connection between RNA-methyltransferases (RNA-MTases) and stress and development processes. However, compared to their animal and bacteria counterparts, the understanding of RNA methyltransferases is still incipient, particularly those located in organelles. Comparative and systematic analyses allowed the tracing of the evolution of these enzymes suggesting the existence of several methyltransferases yet to be characterised. This review outlines the functions of plant nuclear and organellar RNA-MTases in plant development and stress responses and the comparative and evolutionary discoveries made on RNA-MTases across kingdoms.
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Affiliation(s)
- Ricardo Ferraz
- Centre for Functional Ecology, TERRA Associate Laboratory, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, Coimbra 3000-456, Portugal; LAQV Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal.
| | - Sílvia Coimbra
- University of Porto, Faculty of Sciences, Portugal; LAQV Requimte, Sustainable Chemistry, University of Porto, Porto, Portugal.
| | - Sandra Correia
- Centre for Functional Ecology, TERRA Associate Laboratory, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, Coimbra 3000-456, Portugal.
| | - Jorge Canhoto
- Centre for Functional Ecology, TERRA Associate Laboratory, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, Coimbra 3000-456, Portugal.
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Spotting the Targets of the Apospory Controller TGS1 in Paspalum notatum. PLANTS 2022; 11:plants11151929. [PMID: 35893633 PMCID: PMC9332697 DOI: 10.3390/plants11151929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/27/2022] [Accepted: 06/30/2022] [Indexed: 11/17/2022]
Abstract
Sexuality and apomixis are interconnected plant reproductive routes possibly behaving as polyphenic traits under the influence of the environment. In the subtropical grass Paspalum notatum, one of the controllers of apospory, a main component of gametophytic apomixis reproduction, is TRIMETHYLGUANOSINE SYNTHASE 1 (TGS1), a multifunctional gene previously associated with RNA cleavage regulation (including mRNA splicing as well as rRNA and miRNA processing), transcriptional modulation and the establishment of heterochromatin. In particular, the downregulation of TGS1 induces a sexuality decline and the emergence of aposporous-like embryo sacs. The present work was aimed at identifying TGS1 target RNAs expressed during reproductive development of Paspalum notatum. First, we mined available RNA databases originated from spikelets of sexual and apomictic plants, which naturally display a contrasting TGS1 representation, to identify differentially expressed mRNA splice variants and miRNAs. Then, the role of TGS1 in the generation of these particular molecules was investigated in antisense tgs1 sexual lines. We found that CHLOROPHYLL A-B BINDING PROTEIN 1B-21 (LHC Ib-21, a component of the chloroplast light harvesting complex), QUI-GON JINN (QGJ, encoding a MAP3K previously associated with apomixis) and miR2275 (a meiotic 24-nt phasi-RNAs producer) are directly or indirectly targeted by TGS1. Our results point to a coordinated control exercised by signal transduction and siRNA machineries to induce the transition from sexuality to apomixis.
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Variation of Residual Sexuality Rates along Reproductive Development in Apomictic Tetraploids of Paspalum. PLANTS 2022; 11:plants11131639. [PMID: 35807591 PMCID: PMC9269205 DOI: 10.3390/plants11131639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/17/2022] [Accepted: 06/17/2022] [Indexed: 11/30/2022]
Abstract
Most apomictic plants are facultative, maintaining the ability to reproduce sexually at different frequencies depending on the taxa, ploidy, and reproductive stage. In this context, Paspalum species are good model systems for studies evaluating the varying levels of apomixis expression. We aimed to identify, in apomictic tetraploid Paspalum species, the degree of apomixis and residual sexuality in three stages of reproductive development, and if their expression varies along them in order to predict their realized impact on the genetic diversity of future generations. Three main stages in the reproductive development (i.e., ovule, seed, and progeny) were studied in tetraploids from populations of P. cromyorhizon and P. maculosum. Mature ovules were studied using cytoembryological analysis, seeds by flow cytometry, and progeny tests with molecular markers. The expression of sexuality and apomixis was compared in each stage. We observed a decline in expression of sexual reproduction through the consecutive stages, jointly with an increase of apomixis expression. Both species showed at least one tetraploid plant capable of producing progeny by sexual means. These small rates of sexually originated progeny prove the ability of apomictic plants to produce low levels of genetic variation through rare events of sexuality. This study also demonstrates the importance of analyzing different reproductive stages in order to get a whole picture of the reproductive outcomes in plant evolution.
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Siena LA, Azzaro CA, Podio M, Stein J, Leblanc O, Pessino SC, Ortiz JPA. The Auxin-Response Repressor IAA30 Is Down-Regulated in Reproductive Tissues of Apomictic Paspalum notatum. PLANTS 2022; 11:plants11111472. [PMID: 35684245 PMCID: PMC9182604 DOI: 10.3390/plants11111472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 04/20/2022] [Accepted: 05/18/2022] [Indexed: 11/25/2022]
Abstract
The capacity for apomixis in Paspalum notatum is controlled by a single-dominant genomic region, which shows strong synteny to a portion of rice chromosome 12 long arm. The locus LOC_Os12g40890, encoding the Auxin/Indole-3-Acetic Acid (Aux/IAA) family member OsIAA30, is located in this rice genomic segment. The objectives of this work were to identify transcripts coding for Aux/IAA proteins expressed in reproductive tissues of P. notatum, detect the OsIAA30 putative ortholog and analyze its temporal and spatial expression pattern in reproductive organs of sexual and apomictic plants. Thirty-three transcripts coding for AUX/IAA proteins were identified. Predicted protein alignment and phylogenetic analysis detected a highly similar sequence to OsIAA30 (named as PnIAA30) present in both sexual and apomictic samples. The expression assays of PnIAA30 showed a significant down-regulation in apomictic spikelets compared to sexual ones at the stages of anthesis and post-anthesis, representation levels negatively correlated with apospory expressivity and different localizations in sexual and apomictic ovules. Several PnIAA30 predicted interactors also appeared differentially regulated in the sexual and apomictic floral transcriptomes. Our results showed that an auxin-response repressor similar to OsIAA30 is down-regulated in apomictic spikelets of P. notatum and suggests a contrasting regulation of auxin signaling during sexual and asexual seed formation.
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Affiliation(s)
- Lorena Adelina Siena
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
| | - Celeste Antonela Azzaro
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
| | - Maricel Podio
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
| | - Juliana Stein
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
| | - Olivier Leblanc
- DIADE, Université de Montpellier, IRD, CIRAD, 34394 Montpellier, France;
| | - Silvina Claudia Pessino
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
| | - Juan Pablo Amelio Ortiz
- Laboratorio de Biología Molecular, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR) CONICET-UNR, Facultad de Ciencias Agrarias, Campo Experimental Villarino, Universidad Nacional de Rosario, Zavalla S2125ZAA, Santa Fe, Argentina; (L.A.S.); (C.A.A.); (M.P.); (J.S.); (S.C.P.)
- Correspondence: ; Tel.: +54-341-4970080/85 (ext. 1180)
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Bellido AM, Souza Canadá ED, Permingeat HR, Echenique V. Genetic Transformation of Apomictic Grasses: Progress and Constraints. FRONTIERS IN PLANT SCIENCE 2021; 12:768393. [PMID: 34804102 PMCID: PMC8602796 DOI: 10.3389/fpls.2021.768393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/05/2021] [Indexed: 05/17/2023]
Abstract
The available methods for plant transformation and expansion beyond its limits remain especially critical for crop improvement. For grass species, this is even more critical, mainly due to drawbacks in in vitro regeneration. Despite the existence of many protocols in grasses to achieve genetic transformation through Agrobacterium or biolistic gene delivery, their efficiencies are genotype-dependent and still very low due to the recalcitrance of these species to in vitro regeneration. Many plant transformation facilities for cereals and other important crops may be found around the world in universities and enterprises, but this is not the case for apomictic species, many of which are C4 grasses. Moreover, apomixis (asexual reproduction by seeds) represents an additional constraint for breeding. However, the transformation of an apomictic clone is an attractive strategy, as the transgene is immediately fixed in a highly adapted genetic background, capable of large-scale clonal propagation. With the exception of some species like Brachiaria brizantha which is planted in approximately 100 M ha in Brazil, apomixis is almost non-present in economically important crops. However, as it is sometimes present in their wild relatives, the main goal is to transfer this trait to crops to fix heterosis. Until now this has been a difficult task, mainly because many aspects of apomixis are unknown. Over the last few years, many candidate genes have been identified and attempts have been made to characterize them functionally in Arabidopsis and rice. However, functional analysis in true apomictic species lags far behind, mainly due to the complexity of its genomes, of the trait itself, and the lack of efficient genetic transformation protocols. In this study, we review the current status of the in vitro culture and genetic transformation methods focusing on apomictic grasses, and the prospects for the application of new tools assayed in other related species, with two aims: to pave the way for discovering the molecular pathways involved in apomixis and to develop new capacities for breeding purposes because many of these grasses are important forage or biofuel resources.
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Affiliation(s)
- Andrés M. Bellido
- Departamento de Agronomía, Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS – CCT – CONICET Bahía Blanca), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | | | | | - Viviana Echenique
- Departamento de Agronomía, Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS – CCT – CONICET Bahía Blanca), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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Soliman M, Bocchini M, Stein J, Ortiz JPA, Albertini E, Delgado L. Environmental and Genetic Factors Affecting Apospory Expressivity in Diploid Paspalum rufum. PLANTS 2021; 10:plants10102100. [PMID: 34685909 PMCID: PMC8537111 DOI: 10.3390/plants10102100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 11/30/2022]
Abstract
In angiosperms, gametophytic apomixis (clonal reproduction through seeds) is strongly associated with polyploidy and hybridization. The trait is facultative and its expressivity is highly variable between genotypes. Here, we used an F1 progeny derived from diploid apomictic (aposporic) genotypes of Paspalum rufum and two F2 families, derived from F1 hybrids with different apospory expressivity (%AES), to analyze the influence of the environment and the transgenerational transmission of the trait. In addition, AFLP markers were developed in the F1 population to identify genomic regions associated with the %AES. Cytoembryological analyses showed that the %AES was significantly influenced by different environments, but remained stable across the years. F1 and F2 progenies showed a wide range of %AES variation, but most hybrids were not significantly different from the parental genotypes. Maternal and paternal genetic linkage maps were built covering the ten expected linkage groups (LG). A single-marker analysis detected at least one region of 5.7 cM on LG3 that was significantly associated with apospory expressivity. Our results underline the importance of environmental influence in modulating apospory expressivity and identified a genomic region associated with apospory expressivity at the diploid level.
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Affiliation(s)
- Mariano Soliman
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Rosario S2125ZAA, Zavalla, Argentina; (M.S.); (J.S.); (J.P.A.O.)
| | - Marika Bocchini
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (M.B.); (E.A.)
| | - Juliana Stein
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Rosario S2125ZAA, Zavalla, Argentina; (M.S.); (J.S.); (J.P.A.O.)
| | - Juan Pablo A. Ortiz
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Rosario S2125ZAA, Zavalla, Argentina; (M.S.); (J.S.); (J.P.A.O.)
| | - Emidio Albertini
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (M.B.); (E.A.)
| | - Luciana Delgado
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Rosario S2125ZAA, Zavalla, Argentina; (M.S.); (J.S.); (J.P.A.O.)
- Correspondence:
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Taylor CM, Garg G, Berger JD, Ribalta FM, Croser JS, Singh KB, Cowling WA, Kamphuis LG, Nelson MN. A Trimethylguanosine Synthase1-like (TGS1) homologue is implicated in vernalisation and flowering time control. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:3411-3426. [PMID: 34258645 PMCID: PMC8440268 DOI: 10.1007/s00122-021-03910-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 07/06/2021] [Indexed: 05/30/2023]
Abstract
KEY MESSAGE A plant-specific Trimethylguanosine Synthase1-like homologue was identified as a candidate gene for the efl mutation in narrow-leafed lupin, which alters phenology by reducing vernalisation requirement. The vernalisation pathway is a key component of flowering time control in plants from temperate regions but is not well understood in the legume family. Here we examined vernalisation control in the temperate grain legume species, narrow-leafed lupin (Lupinus angustifolius L.), and discovered a candidate gene for an ethylene imine mutation (efl). The efl mutation changes phenology from late to mid-season flowering and additionally causes transformation from obligate to facultative vernalisation requirement. The efl locus was mapped to pseudochromosome NLL-10 in a recombinant inbred line (RIL) mapping population developed by accelerated single seed descent. Candidate genes were identified in the reference genome, and a diverse panel of narrow-leafed lupins was screened to validate mutations specific to accessions with efl. A non-synonymous SNP mutation within an S-adenosyl-L-methionine-dependent methyltransferase protein domain of a Trimethylguanosine Synthase1-like (TGS1) orthologue was identified as the candidate mutation giving rise to efl. This mutation caused substitution of an amino acid within an established motif at a position that is otherwise highly conserved in several plant families and was perfectly correlated with the efl phenotype in F2 and F6 genetic population and a panel of diverse accessions, including the original efl mutant. Expression of the TGS1 homologue did not differ between wild-type and efl genotypes, supporting altered functional activity of the gene product. This is the first time a TGS1 orthologue has been associated with vernalisation response and flowering time control in any plant species.
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Affiliation(s)
- Candy M Taylor
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia
| | - Gagan Garg
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Floreat, WA, 6014, Australia
| | - Jens D Berger
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Floreat, WA, 6014, Australia
| | - Federico M Ribalta
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
| | - Janine S Croser
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia
| | - Karam B Singh
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Floreat, WA, 6014, Australia
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, 6102, Australia
| | - Wallace A Cowling
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia.
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia.
| | - Lars G Kamphuis
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Floreat, WA, 6014, Australia
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, 6102, Australia
| | - Matthew N Nelson
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Floreat, WA, 6014, Australia
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Soliman M, Podio M, Marconi G, Di Marsico M, Ortiz JPA, Albertini E, Delgado L. Differential Epigenetic Marks Are Associated with Apospory Expressivity in Diploid Hybrids of Paspalum rufum. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10040793. [PMID: 33920644 PMCID: PMC8072704 DOI: 10.3390/plants10040793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
Apomixis seems to emerge from the deregulation of preexisting genes involved in sexuality by genetic and/or epigenetic mechanisms. The trait is associated with polyploidy, but diploid individuals of Paspalum rufum can form aposporous embryo sacs and develop clonal seeds. Moreover, diploid hybrid families presented a wide apospory expressivity variation. To locate methylation changes associated with apomixis expressivity, we compare relative DNA methylation levels, at CG, CHG, and CHH contexts, between full-sib P. rufum diploid genotypes presenting differential apospory expressivity. The survey was performed using a methylation content-sensitive enzyme ddRAD (MCSeEd) strategy on samples at premeiosis/meiosis and postmeiosis stages. Based on the relative methylation level, principal component analysis and heatmaps, clearly discriminate samples with contrasting apospory expressivity. Differential methylated contigs (DMCs) showed 14% of homology to known transcripts of Paspalum notatum reproductive transcriptome, and almost half of them were also differentially expressed between apomictic and sexual samples. DMCs showed homologies to genes involved in flower growth, development, and apomixis. Moreover, a high proportion of DMCs aligned on genomic regions associated with apomixis in Setaria italica. Several stage-specific differential methylated sequences were identified as associated with apospory expressivity, which could guide future functional gene characterization in relation to apomixis success at diploid and tetraploid levels.
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Affiliation(s)
- Mariano Soliman
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Maricel Podio
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Gianpiero Marconi
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Marco Di Marsico
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Juan Pablo A. Ortiz
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Emidio Albertini
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Luciana Delgado
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
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A study of the heterochronic sense/antisense RNA representation in florets of sexual and apomictic Paspalum notatum. BMC Genomics 2021; 22:185. [PMID: 33726667 PMCID: PMC7962388 DOI: 10.1186/s12864-021-07450-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/18/2021] [Indexed: 11/10/2022] Open
Abstract
Background Apomixis, an asexual mode of plant reproduction, is a genetically heritable trait evolutionarily related to sexuality, which enables the fixation of heterozygous genetic combinations through the development of maternal seeds. Recently, reference floral transcriptomes were generated from sexual and apomictic biotypes of Paspalum notatum, one of the most well-known plant models for the study of apomixis. However, the transcriptome dynamics, the occurrence of apomixis vs. sexual expression heterochronicity across consecutive developmental steps and the orientation of transcription (sense/antisense) remain unexplored. Results We produced 24 Illumina TruSeq®/ Hiseq 1500 sense/antisense floral transcriptome libraries covering four developmental stages (premeiosis, meiosis, postmeiosis, and anthesis) in biological triplicates, from an obligate apomictic and a full sexual genotype. De novo assemblies with Trinity yielded 103,699 and 100,114 transcripts for the apomictic and sexual samples respectively. A global comparative analysis involving reads from all developmental stages revealed 19,352 differentially expressed sense transcripts, of which 13,205 (68%) and 6147 (32%) were up- and down-regulated in apomictic samples with respect to the sexual ones. Interestingly, 100 differentially expressed antisense transcripts were detected, 55 (55%) of them up- and 45 (45%) down-regulated in apomictic libraries. A stage-by-stage comparative analysis showed a higher number of differentially expressed candidates due to heterochronicity discrimination: the highest number of differential sense transcripts was detected at premeiosis (23,651), followed by meiosis (22,830), postmeiosis (19,100), and anthesis (17,962), while the highest number of differential antisense transcripts were detected at anthesis (495), followed by postmeiosis (164), meiosis (120) and premeiosis (115). Members of the AP2, ARF, MYB and WRKY transcription factor families, as well as the auxin, jasmonate and cytokinin plant hormone families appeared broadly deregulated. Moreover, the chronological expression profile of several well-characterized apomixis controllers was examined in detail. Conclusions This work provides a quantitative sense/antisense gene expression catalogue covering several subsequent reproductive developmental stages from premeiosis to anthesis for apomictic and sexual P. notatum, with potential to reveal heterochronic expression between reproductive types and discover sense/antisense mediated regulation. We detected a contrasting transcriptional and hormonal control in apomixis and sexuality as well as specific sense/antisense modulation occurring at the onset of parthenogenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07450-3.
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Ortiz JPA, Pupilli F, Acuña CA, Leblanc O, Pessino SC. How to Become an Apomixis Model: The Multifaceted Case of Paspalum. Genes (Basel) 2020; 11:E974. [PMID: 32839398 PMCID: PMC7564465 DOI: 10.3390/genes11090974] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/14/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022] Open
Abstract
In the past decades, the grasses of the Paspalum genus have emerged as a versatile model allowing evolutionary, genetic, molecular, and developmental studies on apomixis as well as successful breeding applications. The rise of such an archetypal system progressed through integrative phases, which were essential to draw conclusions based on solid standards. Here, we review the steps adopted in Paspalum to establish the current body of knowledge on apomixis and provide model breeding programs for other agronomically important apomictic crops. In particular, we discuss the need for previous detailed cytoembryological and cytogenetic germplasm characterization; the establishment of sexual and apomictic materials of identical ploidy level; the development of segregating populations useful for inheritance analysis, positional mapping, and epigenetic control studies; the development of omics data resources; the identification of key molecular pathways via comparative gene expression studies; the accurate molecular characterization of genomic loci governing apomixis; the in-depth functional analysis of selected candidate genes in apomictic and model species; the successful building of a sexual/apomictic combined breeding scheme.
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Affiliation(s)
- Juan Pablo A. Ortiz
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, S2125ZAA Zavalla, Argentina;
| | - Fulvio Pupilli
- Institute of Biosciences and Bioresources (IBBR-CNR), 06128 Perugia, Italy;
| | - Carlos A. Acuña
- Instituto de Botánica del Nordeste (IBONE), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste, 3400 Corrientes, Argentina;
| | - Olivier Leblanc
- UMR DIADE, IRD, Univ. Montpellier, 34090 Montpellier, France;
| | - Silvina C. Pessino
- Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, S2125ZAA Zavalla, Argentina;
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Hojsgaard D. Apomixis Technology: Separating the Wheat from the Chaff. Genes (Basel) 2020; 11:E411. [PMID: 32290084 PMCID: PMC7231277 DOI: 10.3390/genes11040411] [Citation(s) in RCA: 15] [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: 03/12/2020] [Revised: 04/03/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023] Open
Abstract
Projections indicate that current plant breeding approaches will be unable to incorporate the global crop yields needed to deliver global food security. Apomixis is a disruptive innovation by which a plant produces clonal seeds capturing heterosis and gene combinations of elite phenotypes. Introducing apomixis into hybrid cultivars is a game-changing development in the current plant breeding paradigm that will accelerate the generation of high-yield cultivars. However, apomixis is a developmentally complex and genetically multifaceted trait. The central problem behind current constraints to apomixis breeding is that the genomic configuration and molecular mechanism that initiate apomixis and guide the formation of a clonal seed are still unknown. Today, not a single explanation about the origin of apomixis offer full empirical coverage, and synthesizing apomixis by manipulating individual genes has failed or produced little success. Overall evidence suggests apomixis arise from a still unknown single event molecular mechanism with multigenic effects. Disentangling the genomic basis and complex genetics behind the emergence of apomixis in plants will require the use of novel experimental approaches benefiting from Next Generation Sequencing technologies and targeting not only reproductive genes, but also the epigenetic and genomic configurations associated with reproductive phenotypes in homoploid sexual and apomictic carriers. A comprehensive picture of most regulatory changes guiding apomixis emergence will be central for successfully installing apomixis into the target species by exploiting genetic modification techniques.
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Affiliation(s)
- Diego Hojsgaard
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, Georg-August-University of Göttingen, Untere Karspüle 2, D-37073-1 Göttingen, Germany
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Lentini Z, Tabares E, Buitrago ME. Vibratome Sectioning and Clearing for Easing Studies of Cassava Embryo Formation. FRONTIERS IN PLANT SCIENCE 2020; 11:1180. [PMID: 32849730 PMCID: PMC7417605 DOI: 10.3389/fpls.2020.01180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/21/2020] [Indexed: 05/09/2023]
Abstract
This work describes the application of clearing on vibratome sections to study the embryo formation in cassava. This procedure provides high-resolution images and reduces significantly the number of sections that need to be analyzed per ovule. This methodology was instrumental for the development of the protocol for embryo rescue in cassava. It has been also applied to monitor the embryo formation response when optimizing seed setting from regular and broad crosses for cassava breeding. Broad crosses between cassava and castor bean (incompatible-euphorbiaceae species) were made aiming to induce doubled haploids through the elimination of the incompatible-male parent genome as done in cereals. Castor bean is widely available and provides continues supply of pollen. Our results suggest that this methodology is easy and effective to assess the response of hundreds of cassava ovules pollinated with castor bean pollen, allowing the identification of multicellular structures in the embryo sac without apparent formation of endosperm. The protocol is also useful when developing and optimizing a methodology to induce doubled haploids in cassava via gynogenesis or from ovules pollinated with irradiated cassava pollen.
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