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Rojek J, Ohad N. The phenomenon of autonomous endosperm in sexual and apomictic plants. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4324-4348. [PMID: 37155961 PMCID: PMC10433939 DOI: 10.1093/jxb/erad168] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/04/2023] [Indexed: 05/10/2023]
Abstract
Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In sexually-reproducing flowering plants, it generally develops after fertilization. However, autonomous endosperm (AE) formation (i.e. independent of fertilization) is also possible. Recent findings of AE loci/ genes and aberrant imprinting in native apomicts, together with a successful initiation of parthenogenesis in rice and lettuce, have enhanced our understanding of the mechanisms bridging sexual and apomictic seed formation. However, the mechanisms driving AE development are not well understood. This review presents novel aspects related to AE development in sexual and asexual plants underlying stress conditions as the primary trigger for AE. Both application of hormones to unfertilized ovules and mutations that impair epigenetic regulation lead to AE development in sexual Arabidopsis thaliana, which may point to a common pathway for both phenomena. Apomictic-like AE development under experimental conditions can take place due to auxin-dependent gene expression and/or DNA methylation.
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Affiliation(s)
- Joanna Rojek
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Nir Ohad
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
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2
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Mahlandt A, Singh DK, Mercier R. Engineering apomixis in crops. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:131. [PMID: 37199785 DOI: 10.1007/s00122-023-04357-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/04/2023] [Indexed: 05/19/2023]
Abstract
Apomixis is an asexual mode of reproduction through seeds where progeny are clones of the mother plants. Naturally apomictic modes of reproduction are found in hundreds of plant genera distributed across more than 30 plant families, but are absent in major crop plants. Apomixis has the potential to be a breakthrough technology by allowing the propagation through seed of any genotype, including F1 hybrids. Here, we have summarized the recent progress toward synthetic apomixis, where combining targeted modifications of both the meiosis and fertilization processes leads to the production of clonal seeds at high frequencies. Despite some remaining challenges, the technology has approached a level of maturity that allows its consideration for application in the field.
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Affiliation(s)
- Alexander Mahlandt
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, Germany
| | - Dipesh Kumar Singh
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, Germany
| | - Raphael Mercier
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, Germany.
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3
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Kolarčik V, Kocová V, Mikoláš V, Mártonfiová L, Hajdučeková N, Mártonfi P. Variability of Reproduction Pathways in the Central-European Populations of Hawthorns with Emphasis on Triploids. PLANTS (BASEL, SWITZERLAND) 2022; 11:3497. [PMID: 36559608 PMCID: PMC9786806 DOI: 10.3390/plants11243497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/21/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The role of apomeiosis, parthenogenesis, and pseudogamy in the asexual reproduction of some plant groups has not been fully elucidated in relation to species diversification. Quantitative analyses of seed origin may help in gaining better understanding of intercytotypic interactions. Asexual reproduction associated with polyploidy and frequent hybridization plays a crucial role in the evolutionary history of the genus Crataegus in North America. In Europe, the genus represents a taxonomically complex and very difficult species group not often studied using a modern biosystematic approach. We investigated the reproduction pathways in mixed-cytotype populations of selected taxa of Crataegus in eastern Slovakia, Central Europe. The investigated accessions were characterized by seed production data and the ploidy level of mature plants as well as the embryo and endosperm tissues of their seeds determined via flow cytometry. Diploid and polyploid hawthorns reproduce successfully; they also produce high numbers of seeds. An exception is represented by an almost sterile triploid. Diploids reproduce sexually. Polyploids shift to asexual reproduction, but pseudogamy seems to be essential for regular seed development. In rare cases, fertilization of unreduced gametes occurs, which offers opportunity for the establishment of new polyploid cytotypes between diploid sexuals and polyploid asexuals. Opposite to sexual diploids, triploids are obligate, and tetraploids almost obligate apomicts. Apomixis is considered to help stabilize individual weakly differentiated polyploid microspecies. Pseudogamy is a common feature and usually leads to unbalanced maternal to paternal contribution in the endosperm of triploid accessions. Parental contribution to endosperm gene dosage is somehow relaxed in triploids. Our Crataegus plant system resembles reproduction in the diploids and polyploids of North American hawthorns. Our data provide support for the hypothesis that polyploidization, shifts in reproduction modes, and hybridization shape the genus diversity also in Central Europe.
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Affiliation(s)
- Vladislav Kolarčik
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, Slovakia
| | - Valéria Kocová
- Botanical Garden, Pavol Jozef Šafárik University, Mánesova 23, SK-043 52 Košice, Slovakia
| | | | - Lenka Mártonfiová
- Botanical Garden, Pavol Jozef Šafárik University, Mánesova 23, SK-043 52 Košice, Slovakia
| | | | - Pavol Mártonfi
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, Slovakia
- Botanical Garden, Pavol Jozef Šafárik University, Mánesova 23, SK-043 52 Košice, Slovakia
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4
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Paczesniak D, Pellino M, Goertzen R, Guenter D, Jahnke S, Fischbach A, Lovell JT, Sharbel TF. Seed size, endosperm and germination variation in sexual and apomictic Boechera. FRONTIERS IN PLANT SCIENCE 2022; 13:991531. [PMID: 36466233 PMCID: PMC9716183 DOI: 10.3389/fpls.2022.991531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Asexual reproduction results in offspring that are genetically identical to the mother. Among apomictic plants (reproducing asexually through seeds) many require paternal genetic contribution for proper endosperm development (pseudogamous endosperm). We examined phenotypic diversity in seed traits using a diverse panel of sexual and apomictic accessions from the genus Boechera. While genetic uniformity resulting from asexual reproduction is expected to reduce phenotypic diversity in seeds produced by apomictic individuals, pseudogamous endosperm, variable endosperm ploidy, and the deviations from 2:1 maternal:paternal genome ratio in endosperm can all contribute to increased phenotypic diversity among apomictic offspring. We characterized seed size variation in 64 diploid sexual and apomictic (diploid and triploid) Boechera lineages. In order to find out whether individual seed size was related to endosperm ploidy we performed individual seed measurements (projected area and mass) using the phenoSeeder robot system and flow cytometric seed screen. In order to test whether individual seed size had an effect on resulting fitness we performed a controlled growth experiment and recorded seedling life history traits (germination success, germination timing, and root growth rate). Seeds with triploid embryos were 33% larger than those with diploid embryos, but no average size difference was found between sexual and apomictic groups. We identified a maternal effect whereby chloroplast lineage 2 had 30% larger seeds than lineage 3, despite having broad and mostly overlapping geographic ranges. Apomictic seeds were not more uniform in size than sexual seeds, despite genetic uniformity of the maternal gametophyte in the former. Among specific embryo/endosperm ploidy combinations, seeds with tetraploid (automomous) endosperm were on average smaller, and the proportion of such seeds was highest in apomicts. Larger seeds germinated more quickly than small seeds, and lead to higher rates of root growth in young seedlings. Seed mass is under balancing selection in Boechera, and it is an important predictor of several traits, including germination probability and timing, root growth rates, and developmental abnormalities in apomictic accessions.
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Affiliation(s)
- Dorota Paczesniak
- Global Institute for Food Security (GIFS), University of Saskatchewan, Saskatoon, SK, Canada
- Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Marco Pellino
- Global Institute for Food Security (GIFS), University of Saskatchewan, Saskatoon, SK, Canada
- Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Richard Goertzen
- Global Institute for Food Security (GIFS), University of Saskatchewan, Saskatoon, SK, Canada
| | - Devan Guenter
- Global Institute for Food Security (GIFS), University of Saskatchewan, Saskatoon, SK, Canada
| | - Siegfried Jahnke
- Forschungszentrum Jülich, Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Jülich, Germany
| | - Andreas Fischbach
- Forschungszentrum Jülich, Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Jülich, Germany
| | - John T. Lovell
- Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Timothy F. Sharbel
- Global Institute for Food Security (GIFS), University of Saskatchewan, Saskatoon, SK, Canada
- Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
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Bakin E, Sezer F, Özbilen A, Kilic I, Uner B, Rayko M, Taskin KM, Brukhin V. Phylogenetic and Expression Analysis of CENH3 and APOLLO Genes in Sexual and Apomictic Boechera Species. PLANTS 2022; 11:plants11030387. [PMID: 35161368 PMCID: PMC8839901 DOI: 10.3390/plants11030387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/22/2022] [Accepted: 01/27/2022] [Indexed: 11/16/2022]
Abstract
Apomictic plants (reproducing via asexual seeds), unlike sexual individuals, avoid meiosis and egg cell fertilization. Consequently, apomixis is very important for fixing maternal genotypes in the next plant generations. Despite the progress in the study of apomixis, molecular and genetic regulation of the latter remains poorly understood. So far APOLLO gene encoding aspartate glutamate aspartate aspartate histidine exonuclease is one of the very few described genes associated with apomixis in Boechera species. The centromere-specific histone H3 variant encoded by CENH3 gene is essential for cell division. Mutations in CENH3 disrupt chromosome segregation during mitosis and meiosis since the attachment of spindle microtubules to a mutated form of the CENH3 histone fails. This paper presents in silico characteristic of APOLLO and CENH3 genes, which may affect apomixis. Furthermore, we characterize the structure of CENH3 by bioinformatic tools, study expression levels of APOLLO and CENH3 transcripts by Real-Time Polymerase Chain Reaction RT-PCR in gynoecium/siliques of the natural diploid apomictic and sexual Boechera species at the stages of meiosis and before and after fertilization. While CENH3 was a single copy gene in all Boechera species, the APOLLO gene have several polymorphic alleles associated with sexual and apomictic reproduction in the Boechera genera. Expression of the APOLLO apo-allele during meiosis was upregulated in gynoecium of apomict B. divaricarpa downregulating after meiosis until the 4th day after pollination (DAP). On the 5th DAP, expression in apomictic siliques increased again. In sexual B. stricta gynoecium and siliques APOLLO apo-allele did not express. Expression of the APOLLO sex-allele during and after meiosis in gynoecium of sexual plants was several times higher than that in apomictic gynoecium. However, after pollination the sex-allele was downregulated in sexual siliques to the level of apomicts and increased sharply on the 5th DAP, while in apomictic siliques it almost did not express. At the meiotic stage, the expression level of CENH3 in the gynoecium of apomicts was two times lower than that of the sexual Boechera, decreasing in both species after meiosis and keep remaining very low in siliques of both species for several days after artificial pollination until the 4th DAP, when the expression level raised in sexual B. stricta siliques exceeding 5 times the level in apomictic B. divaricarpa siliques. We also discuss polymorphism and phylogeny of the APOLLO and CENH3 genes. The results obtained may indicate to a role of the CENH3 and APOLLO genes in the development of apomixis in species of the genus Boechera.
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Affiliation(s)
- Evgeny Bakin
- Bioinformatics Institute, 197342 Saint-Petersburg, Russia;
| | - Fatih Sezer
- Department of Molecular Biology and Genetics, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey; (F.S.); (B.U.)
| | - Aslıhan Özbilen
- Department of Biology, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey; (A.Ö.); (I.K.)
| | - Irem Kilic
- Department of Biology, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey; (A.Ö.); (I.K.)
| | - Buket Uner
- Department of Molecular Biology and Genetics, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey; (F.S.); (B.U.)
| | - Mike Rayko
- Laboratory for Algorithmic Biology, Saint-Petersburg State University, 199004 Saint-Petersburg, Russia;
| | - Kemal Melih Taskin
- Department of Molecular Biology and Genetics, Çanakkale Onsekiz Mart University, Çanakkale 17100, Turkey; (F.S.); (B.U.)
- Correspondence: (K.M.T.); (V.B.)
| | - Vladimir Brukhin
- Plant Genomics Lab, ChemBio Cluster, ITMO University, 191002 Saint-Petersburg, Russia
- Department of Plant Embryology and Reproductive Biology, Komarov Botanical Institute Russian Academy of Sciences, 197376 Saint-Petersburg, Russia
- Correspondence: (K.M.T.); (V.B.)
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Fiaz S, Wang X, Younas A, Alharthi B, Riaz A, Ali H. Apomixis and strategies to induce apomixis to preserve hybrid vigor for multiple generations. GM CROPS & FOOD 2021; 12:57-70. [PMID: 32877304 PMCID: PMC7553744 DOI: 10.1080/21645698.2020.1808423] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/06/2020] [Indexed: 11/16/2022]
Abstract
Hybrid seeds of several important crops with supreme qualities including yield, biotic and abiotic stress tolerance have been cultivated for decades. Thus far, a major challenge with hybrid seeds is that they do not have the ability to produce plants with the same qualities over subsequent generations. Apomixis, an asexual mode of reproduction by avoiding meiosis, exists naturally in flowering plants, and ultimately leads to seed production. Apomixis has the potential to preserve hybrid vigor for multiple generations in economically important plant genotypes. The evolution and genetics of asexual seed production are unclear, and much more effort will be required to determine the genetic architecture of this phenomenon. To fix hybrid vigor, synthetic apomixis has been suggested. The development of MiMe (mitosis instead of meiosis) genotypes has been utilized for clonal gamete production. However, the identification and parental origin of genes responsible for synthetic apomixis are little known and need further clarification. Genome modifications utilizing genome editing technologies (GETs), such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (cas), a reverse genetics tool, have paved the way toward the utilization of emerging technologies in plant molecular biology. Over the last decade, several genes in important crops have been successfully edited. The vast availability of GETs has made functional genomics studies easy to conduct in crops important for food security. Disruption in the expression of genes specific to egg cell MATRILINEAL (MTL) through the CRISPR/Cas genome editing system promotes the induction of haploid seed, whereas triple knockout of the Baby Boom (BBM) genes BBM1, BBM2, and BBM3 cause embryo arrest and abortion, which can be fully rescued by male-transmitted BBM1. The establishment of synthetic apomixis by engineering the MiMe genotype by genome editing of BBM1 expression or disruption of MTL leads to clonal seed production and heritability for multiple generations. In the present review, we discuss current developments related to the use of CRISPR/Cas technology in plants and the possibility of promoting apomixis in crops to preserve hybrid vigor. In addition, genetics, evolution, epigenetic modifications, and strategies for MiMe genotype development are discussed in detail.
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Affiliation(s)
- Sajid Fiaz
- Department of Plant Breeding and Genetics, The University of Haripur 22620 , Khyber Pakhtunkhwa, Pakistan
| | - Xiukang Wang
- College of Life Sciences, Yan'an University , Yan'an, Shaanxi, China
| | - Afifa Younas
- Department of Botany, Lahore College for Women University , Lahore, Pakistan
| | - Badr Alharthi
- College of Science and Engineering, Flinders University , Adelaide, Australia
- University College of Khurma, Taif University , Taif, Saudi Arabia
| | - Adeel Riaz
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences , Beijing, China
| | - Habib Ali
- Department of Agricultural Engineering, Khawaja Fareed University of Engineering and Information Technology , Rahim Yar Khan, Pakistan
- Department of Entomology, Sub-Campus Depalpur, University of Agriculture Faisalabad , Faisalabad, Pakistan
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Ahrens CW, James EA, Miller AD, Scott F, Aitken NC, Jones AW, Lu-Irving P, Borevitz JO, Cantrill DJ, Rymer PD. Spatial, climate and ploidy factors drive genomic diversity and resilience in the widespread grass Themeda triandra. Mol Ecol 2020; 29:3872-3888. [PMID: 32885504 DOI: 10.1111/mec.15614] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 12/27/2022]
Abstract
Global climate change poses a significant threat to natural communities around the world, with many plant species showing signs of climate stress. Grassland ecosystems are not an exception, with climate change compounding contemporary pressures such as habitat loss and fragmentation. In this study, we assess the climate resilience of Themeda triandra, a foundational species and the most widespread plant in Australia, by assessing the relative contributions of spatial, environmental and ploidy factors to contemporary genomic variation. Reduced-representation genome sequencing on 472 samples from 52 locations was used to test how the distribution of genomic variation, including ploidy polymorphism, supports adaptation to hotter and drier climates. We explicitly quantified isolation by distance (IBD) and isolation by environment (IBE) and predicted genomic vulnerability of populations to future climates based on expected deviation from current genomic composition. We found that a majority (54%) of genomic variation could be attributed to IBD, while an additional 22% (27% when including ploidy information) could be explained by two temperature and two precipitation climate variables demonstrating IBE. Ploidy polymorphisms were common within populations (31/52 populations), indicating that ploidy mixing is characteristic of T. triandra populations. Genomic vulnerabilities were found to be heterogeneously distributed throughout the landscape, and our analysis suggested that ploidy polymorphism, along with other factors linked to polyploidy, reduced vulnerability to future climates by 60% (0.25-0.10). Our data suggests that polyploidy may facilitate adaptation to hotter climates and highlight the importance of incorporating ploidy in adaptive management strategies to promote the resilience of this and other foundation species.
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Affiliation(s)
- Collin W Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia.,Royal Botanic Gardens Victoria, Melbourne, VIC, Australia
| | | | - Adam D Miller
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Warrnambool, VIC, Australia
| | - Ferguson Scott
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Nicola C Aitken
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Ashley W Jones
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Patricia Lu-Irving
- Research Centre for Ecosystem Resilience, Australian Institute of Botanical Science, Royal Botanic Garden, Sydney, NSW, Australia
| | - Justin O Borevitz
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | | | - Paul D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
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Brukhin V, Osadtchiy JV, Florez-Rueda AM, Smetanin D, Bakin E, Nobre MS, Grossniklaus U. The Boechera Genus as a Resource for Apomixis Research. FRONTIERS IN PLANT SCIENCE 2019; 10:392. [PMID: 31001306 PMCID: PMC6454215 DOI: 10.3389/fpls.2019.00392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/14/2019] [Indexed: 05/03/2023]
Abstract
The genera Boechera (A. Löve et D. Löve) and Arabidopsis, the latter containing the model plant Arabidopsis thaliana, belong to the same clade within the Brassicaceae family. Boechera is the only among the more than 370 genera in the Brassicaceae where apomixis is well documented. Apomixis refers to the asexual reproduction through seed, and a better understanding of the underlying mechanisms has great potential for applications in agriculture. The Boechera genus currently includes 110 species (of which 38 are reported to be triploid and thus apomictic), which are distributed mostly in the North America. The apomictic lineages of Boechera occur at both the diploid and triploid level and show signs of a hybridogenic origin, resulting in a modification of their chromosome structure, as reflected by alloploidy, aneuploidy, substitutions of homeologous chromosomes, and the presence of aberrant chromosomes. In this review, we discuss the advantages of the Boechera genus to study apomixis, consider its modes of reproduction as well as the inheritance and possible mechanisms controlling apomixis. We also consider population genetic aspects and a possible role of hybridization at the origin of apomixis in Boechera. The molecular tools available to study Boechera, such as transformation techniques, laser capture microdissection, analysis of transcriptomes etc. are also discussed. We survey available genome assemblies of Boechera spp. and point out the challenges to assemble the highly heterozygous genomes of apomictic species. Due to these challenges, we argue for the application of an alternative reference-free method for the comparative analysis of such genomes, provide an overview of genomic sequencing data in the genus Boechera suitable for such analysis, and provide examples of its application.
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Affiliation(s)
- Vladimir Brukhin
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, Saint Petersburg, Russia
- Department of Plant Embryology and Reproductive Biology, Komarov Botanical Institute RAS, Saint Petersburg, Russia
| | - Jaroslaw V. Osadtchiy
- Department of Plant Embryology and Reproductive Biology, Komarov Botanical Institute RAS, Saint Petersburg, Russia
| | - Ana Marcela Florez-Rueda
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Dmitry Smetanin
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Evgeny Bakin
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, Saint Petersburg, Russia
- Bioinformatics Institute, Saint Petersburg, Russia
| | - Margarida Sofia Nobre
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
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Kaushal P, Dwivedi KK, Radhakrishna A, Srivastava MK, Kumar V, Roy AK, Malaviya DR. Partitioning Apomixis Components to Understand and Utilize Gametophytic Apomixis. FRONTIERS IN PLANT SCIENCE 2019; 10:256. [PMID: 30906306 PMCID: PMC6418048 DOI: 10.3389/fpls.2019.00256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/18/2019] [Indexed: 05/07/2023]
Abstract
Apomixis is a method of reproduction to generate clonal seeds and offers tremendous potential to fix heterozygosity and hybrid vigor. The process of apomictic seed development is complex and comprises three distinct components, viz., apomeiosis (leading to formation of unreduced egg cell), parthenogenesis (development of embryo without fertilization) and functional endosperm development. Recently, in many crops, these three components are reported to be uncoupled leading to their partitioning. This review provides insight into the recent status of our understanding surrounding partitioning apomixis components in gametophytic apomictic plants and research avenues that it offers to help understand the biology of apomixis. Possible consequences leading to diversity in seed developmental pathways, resources to understand apomixis, inheritance and identification of candidate gene(s) for partitioned components, as well as contribution towards creation of variability are all discussed. The potential of Panicum maximum, an aposporous crop, is also discussed as a model crop to study partitioning principle and effects. Modifications in cytogenetic status, as well as endosperm imprinting effects arising due to partitioning effects, opens up new opportunities to understand and utilize apomixis components, especially towards synthesizing apomixis in crops.
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Affiliation(s)
- Pankaj Kaushal
- ICAR-National Institute of Biotic Stress Management, Raipur, India
| | | | | | | | - Vinay Kumar
- ICAR-National Institute of Biotic Stress Management, Raipur, India
| | - Ajoy Kumar Roy
- ICAR-Indian Grassland and Fodder Research Institute, Jhansi, India
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10
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León-Martínez G, Vielle-Calzada JP. Apomixis in flowering plants: Developmental and evolutionary considerations. Curr Top Dev Biol 2019; 131:565-604. [DOI: 10.1016/bs.ctdb.2018.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Rojek J, Kapusta M, Kozieradzka-Kiszkurno M, Majcher D, Górniak M, Sliwinska E, Sharbel TF, Bohdanowicz J. Establishing the cell biology of apomictic reproduction in diploid Boechera stricta (Brassicaceae). ANNALS OF BOTANY 2018; 122:513-539. [PMID: 29982367 PMCID: PMC6153484 DOI: 10.1093/aob/mcy114] [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: 02/08/2018] [Accepted: 06/21/2018] [Indexed: 05/15/2023]
Abstract
Background and aims In the Brassicaceae family, apomictic development is characteristic of the genus Boechera. Hybridization, polyploidy and environmental adaptation that arose during the evolution of Boechera may serve as (epi)genetic regulators of apomictic initiation in this genus. Here we focus on Boechera stricta, a predominantly diploid species that reproduces sexually. However, apomictic development in this species has been reported in several studies, indicating non-obligate sexuality. Methods A progressive investigation of flower development was conducted using three accessions to assess the reproductive system of B. stricta. We employed molecular and cyto-embryological identification using histochemistry, transmission electron microscopy and Nomarski and epifluorescence microscopy. Key Results Data from internal transcribed spacer (ITS) and chloroplast haplotype sequencing, in addition to microsatellite variation, confirmed the B. stricta genotype for all lines. Embryological data indicated irregularities in sexual reproduction manifested by heterochronic ovule development, longevity of meiocyte and dyad stages, diverse callose accumulation during meiocyte-to-gametophyte development, and the formation of triads and tetrads in several patterns. The arabinogalactan-related sugar epitope recognized by JIM13 immunolocalized to one or more megaspores. Furthermore, pollen sterility and a high frequency of seed abortion appeared to accompany reproduction of the accession ES512, along with the initiation of parthenogenesis. Data from flow cytometric screening revealed both sexual and apomictic seed formation. Conclusion These results imply that B. stricta is a species with an underlying ability to initiate apomixis, at least with respect to the lines examined here. The existence of apomixis in an otherwise diploid sexual B. stricta may provide the genomic building blocks for establishing highly penetrant apomictic diploids and hybrid relatives. Our findings demonstrate that apomixis per se is a variable trait upon which natural selection could act.
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Affiliation(s)
- Joanna Rojek
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdańsk, Poland
| | - Małgorzata Kapusta
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdańsk, Poland
| | | | - Daria Majcher
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdańsk, Poland
| | - Marcin Górniak
- Department of Molecular Evolution, Faculty of Biology, University of Gdańsk, Poland
| | - Elwira Sliwinska
- Laboratory of Molecular Biology and Cytometry, Department of Agricultural Biotechnology, UTP University of Technology and Life Sciences in Bydgoszcz, Poland
| | - Timothy F Sharbel
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jerzy Bohdanowicz
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdańsk, Poland
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12
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Sharbrough J, Luse M, Boore JL, Logsdon JM, Neiman M. Radical amino acid mutations persist longer in the absence of sex. Evolution 2018. [PMID: 29520921 DOI: 10.1111/evo.13465] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Harmful mutations are ubiquitous and inevitable, and the rate at which these mutations are removed from populations is a critical determinant of evolutionary fate. Closely related sexual and asexual taxa provide a particularly powerful setting to study deleterious mutation elimination because sexual reproduction should facilitate mutational clearance by reducing selective interference between sites and by allowing the production of offspring with different mutational complements than their parents. Here, we compared the rate of removal of conservative (i.e., similar biochemical properties) and radical (i.e., distinct biochemical properties) nonsynonymous mutations from mitochondrial genomes of sexual versus asexual Potamopyrgus antipodarum, a New Zealand freshwater snail characterized by coexisting and ecologically similar sexual and asexual lineages. Our analyses revealed that radical nonsynonymous mutations are cleared at higher rates than conservative changes and that sexual lineages eliminate radical changes more rapidly than asexual counterparts. These results are consistent with reduced efficacy of purifying selection in asexual lineages allowing harmful mutations to remain polymorphic longer than in sexual lineages. Together, these data illuminate some of the population-level processes contributing to mitochondrial mutation accumulation and suggest that mutation accumulation could influence the outcome of competition between sexual and asexual lineages.
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Affiliation(s)
- Joel Sharbrough
- Department of Biology, University of Iowa, Iowa City, Iowa 52242.,Department of Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Meagan Luse
- Department of Biology, University of Iowa, Iowa City, Iowa 52242
| | - Jeffrey L Boore
- Department of Integrative Biology, University of California, Berkeley, Berkeley, California 94720.,Providence St. Joseph Health and Institute for Systems Biology, Seattle, Washington 98109
| | - John M Logsdon
- Department of Biology, University of Iowa, Iowa City, Iowa 52242
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, Iowa 52242
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13
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Taşkin KM, Özbilen A, Sezer F, Hürkan K, Güneş Ş. Structure and expression of dna methyltransferase genes from apomictic and sexual Boechera species. Comput Biol Chem 2017; 67:15-21. [PMID: 28038368 DOI: 10.1016/j.compbiolchem.2016.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/30/2016] [Accepted: 12/09/2016] [Indexed: 10/20/2022]
Abstract
In this study, we determined the structure of DNA methyltransferase (DNMT) genes in apomict and sexual Boechera species and investigated the expression levels during seed development. Protein and DNA sequences of diploid sexual Boechera stricta DNMT genes obtained from Phytozome 10.3 were used to identify the homologues in apomicts, Boechera holboellii and Boechera divaricarpa. Geneious R8 software was used to map the short-paired reads library of B. holboellii whole genome or B. divaricarpa transcriptome reads to the reference gene sequences. We determined three DNMT genes; for Boechera spp. METHYLTRANSFERASE1 (MET1), CHROMOMETHYLASE 3 (CMT3) and DOMAINS REARRANGED METHYLTRANSFERASE 1/2 (DRM2). We examined the structure of these genes with bioinformatic tools and compared with other DNMT genes in plants. We also examined the levels of expression in silique tissues after fertilization by semi-quantitative PCR. The structure of DNMT proteins in apomict and sexual Boechera species share common features. However, the expression levels of DNMT genes were different in apomict and sexual Boechera species. We found that DRM2 was upregulated in apomictic Boechera species after fertilization. Phylogenetic trees showed that three genes are conserved among green algae, monocotyledons and dicotyledons. Our results indicated a deregulation of DNA methylation machinery during seed development in apomicts.
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Affiliation(s)
- Kemal Melik Taşkin
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey.
| | - Aslıhan Özbilen
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Fatih Sezer
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Kaan Hürkan
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
| | - Şebnem Güneş
- Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Biology, 17100 Çanakkale, Turkey
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14
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Abstract
Apomixis, commonly defined as asexual reproduction through seed, is a reproductive trait that occurs in only a few minor crops, but would be highly valuable in major crops. Apomixis results in seed-derived progenies that are genetically identical to their maternal parent. The advantage of apomixis would lie in seed propagation of elite food, feed, and biofuel crops that are heterozygous such as hybrid corn and switchgrass or self-pollinating crops for which no commercial-scale hybrid production system is available. While hybrid plants often outperform parental lines in growth and higher yields, production of hybrid seed is accomplished through carefully controlled, labor intensive crosses. Both small farmers in developing countries who produce their own seed and commercial companies that market hybrid seed could benefit from the establishment of engineered apomixis in plants. In this chapter, we review what has been learned from studying natural apomicts and mutations in sexual plants leading to apomixis-like development, plus discuss how the components of apomixis could be successfully engineered in plants.
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Affiliation(s)
- Joann A Conner
- Horticulture Department, NESPAL/University of Georgia-Tifton Campus, 2356 Rainwater Road, Tifton, GA, 31794, USA.
| | - Peggy Ozias-Akins
- Horticulture Department, NESPAL/University of Georgia-Tifton Campus, 2356 Rainwater Road, Tifton, GA, 31794, USA
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia-Tifton Campus, Tifton, GA, USA
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15
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Shah JN, Kirioukhova O, Pawar P, Tayyab M, Mateo JL, Johnston AJ. Depletion of Key Meiotic Genes and Transcriptome-Wide Abiotic Stress Reprogramming Mark Early Preparatory Events Ahead of Apomeiotic Transition. FRONTIERS IN PLANT SCIENCE 2016; 7:1539. [PMID: 27833618 PMCID: PMC5080521 DOI: 10.3389/fpls.2016.01539] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/30/2016] [Indexed: 05/19/2023]
Abstract
Molecular dissection of apomixis - an asexual reproductive mode - is anticipated to solve the enigma of loss of meiotic sex, and to help fixing elite agronomic traits. The Brassicaceae genus Boechera comprises of both sexual and apomictic species, permitting comparative analyses of meiotic circumvention (apomeiosis) and parthenogenesis. Whereas previous studies reported local transcriptome changes during these events, it remained unclear whether global changes associated with hybridization, polyploidy and environmental adaptation that arose during evolution of Boechera might serve as (epi)genetic regulators of early development prior apomictic initiation. To identify these signatures during vegetative stages, we compared seedling RNA-seq transcriptomes of an obligate triploid apomict and a diploid sexual, both isolated from a drought-prone habitat. Uncovered were several genes differentially expressed between sexual and apomictic seedlings, including homologs of meiotic genes ASYNAPTIC 1 (ASY1) and MULTIPOLAR SPINDLE 1 (MPS1) that were down-regulated in apomicts. An intriguing class of apomict-specific deregulated genes included several NAC transcription factors, homologs of which are known to be transcriptionally reprogrammed during abiotic stress in other plants. Deregulation of both meiotic and stress-response genes during seedling stages might possibly be important in preparation for meiotic circumvention, as similar transcriptional alteration was discernible in apomeiotic floral buds too. Furthermore, we noted that the apomict showed better tolerance to osmotic stress in vitro than the sexual, in conjunction with significant upregulation of a subset of NAC genes. In support of the current model that DNA methylation epigenetically regulates stress, ploidy, hybridization and apomixis, we noted that ASY1, MPS1 and NAC019 homologs were deregulated in Boechera seedlings upon DNA demethylation, and ASY1 in particular seems to be repressed by global DNA methylation exclusively in the apomicts. Variability in stress and transcriptional response in a diploid apomict, which is geographically distinct from the triploid apomict, pinpoints both common and independent features of apomixis evolution. Our study provides a molecular frame-work to investigate how the adaptive traits associated with the evolutionary history of apomicts co-adapted with meiotic gene deregulation at early developmental stage, in order to predate meiotic recombination, which otherwise is thought to be favorable in stress and low-fitness conditions.
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Affiliation(s)
- Jubin N. Shah
- Laboratory of Germline Genetics & Evo-Devo, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Olga Kirioukhova
- Laboratory of Germline Genetics & Evo-Devo, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
- Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
| | - Pallavi Pawar
- Laboratory of Germline Genetics & Evo-Devo, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Muhammad Tayyab
- Laboratory of Germline Genetics & Evo-Devo, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
| | - Juan L. Mateo
- Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
- *Correspondence: Amal J. Johnston, ; Juan L. Mateo,
| | - Amal J. Johnston
- Laboratory of Germline Genetics & Evo-Devo, Centre for Organismal Studies, University of HeidelbergHeidelberg, Germany
- Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
- *Correspondence: Amal J. Johnston, ; Juan L. Mateo,
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16
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Mangla Y, Chaudhary M, Gupta H, Thakur R, Goel S, Raina SN, Tandon R. Facultative apomixis and development of fruit in a deciduous shrub with medicinal and nutritional uses. AOB PLANTS 2015; 7:plv098. [PMID: 26286224 PMCID: PMC4589571 DOI: 10.1093/aobpla/plv098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/27/2015] [Indexed: 06/04/2023]
Abstract
Knowledge of reproductive biology of plants is crucial to understand their natural mode of propagation, which may aid in conservation and crop improvement. The reproductive details are also crucial for beginning the cultivation of a potential crop on a commercial scale. Fruits of sea buckthorn, Hippophae rhamnoides, are used in a variety of medicinal and nutritional products. So far, fruits are collected from the female plants in the wild. It is known that the species fruits profusely and also propagates by forming root suckers, but the details of sexual reproduction are not available. We investigated the mode of reproduction and development of fruits from natural populations of sea buckthorn. Megasporogenesis and megagametogenesis were studied through resin-embedded sectioning and ovule-clearing methods, and fruit development through histochemistry. The study of mitosis and male meiosis showed that the plants at the site were diploid (2n = 2x = 24). The embryo sac may develop either through the monosporic pathway and differentiates into 'Polygonum type' or aposporously into 'Panicum type'. The embryo may develop by sexual and adventitious pathways. Thus, sea buckthorn is a facultative apomict. The occurrence of diverse reproductive pathways assures the possibility of generation of novel genotypes through sexuality, while apomictic reproduction maintains adaptive genotypes and ensures reproduction in the absence of pollination. Anatomical details suggest that the fruit of sea buckthorn may be appropriately described as a pseudo-drupe.
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Affiliation(s)
- Yash Mangla
- Department of Botany, University of Delhi, Delhi 110 007, India
| | - Manju Chaudhary
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 210 303, India
| | - Himshikha Gupta
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 210 303, India
| | - Rakesh Thakur
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 210 303, India
| | - Shailendra Goel
- Department of Botany, University of Delhi, Delhi 110 007, India
| | - S N Raina
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 210 303, India
| | - Rajesh Tandon
- Department of Botany, University of Delhi, Delhi 110 007, India
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17
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Rodríguez-Leal D, León-Martínez G, Abad-Vivero U, Vielle-Calzada JP. Natural variation in epigenetic pathways affects the specification of female gamete precursors in Arabidopsis. THE PLANT CELL 2015; 27:1034-45. [PMID: 25829442 PMCID: PMC4558685 DOI: 10.1105/tpc.114.133009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/23/2015] [Accepted: 03/01/2015] [Indexed: 05/03/2023]
Abstract
In angiosperms, the transition to the female gametophytic phase relies on the specification of premeiotic gamete precursors from sporophytic cells in the ovule. In Arabidopsis thaliana, a single diploid cell is specified as the premeiotic female gamete precursor. Here, we show that ecotypes of Arabidopsis exhibit differences in megasporogenesis leading to phenotypes reminiscent of defects in dominant mutations that epigenetically affect the specification of female gamete precursors. Intraspecific hybridization and polyploidy exacerbate these defects, which segregate quantitatively in F2 populations derived from ecotypic hybrids, suggesting that multiple loci control cell specification at the onset of female meiosis. This variation in cell differentiation is influenced by the activity of ARGONAUTE9 (AGO9) and RNA-DEPENDENT RNA POLYMERASE6 (RDR6), two genes involved in epigenetic silencing that control the specification of female gamete precursors. The pattern of transcriptional regulation and localization of AGO9 varies among ecotypes, and abnormal gamete precursors in ovules defective for RDR6 share identity with ectopic gamete precursors found in selected ecotypes. Our results indicate that differences in the epigenetic control of cell specification lead to natural phenotypic variation during megasporogenesis. We propose that this mechanism could be implicated in the emergence and evolution of the reproductive alternatives that prevail in flowering plants.
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Affiliation(s)
- Daniel Rodríguez-Leal
- Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad y Departamento de Ingeniería Genética de Plantas, Cinvestav Irapuato CP36821 Guanajuato, Mexico
| | - Gloria León-Martínez
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional del Instituto Politécnico Nacional, Unidad Michoacán, CP 59510 Jiquilpan, Mexico
| | - Ursula Abad-Vivero
- Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad y Departamento de Ingeniería Genética de Plantas, Cinvestav Irapuato CP36821 Guanajuato, Mexico
| | - Jean-Philippe Vielle-Calzada
- Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad y Departamento de Ingeniería Genética de Plantas, Cinvestav Irapuato CP36821 Guanajuato, Mexico
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18
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Rodriguez-Leal D, Vielle-Calzada JP. Regulation of apomixis: learning from sexual experience. CURRENT OPINION IN PLANT BIOLOGY 2012; 15:549-55. [PMID: 23000434 DOI: 10.1016/j.pbi.2012.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/17/2012] [Accepted: 09/05/2012] [Indexed: 05/10/2023]
Abstract
Apomixis is a natural form of asexual reproduction through seeds that leads to viable offspring genetically identical to the mother plant. New evidence from sexual model species indicates that the regulation of female gametogenesis and seed formation is also directed by epigenetic mechanisms that are crucial to control events that distinguish sexuality from apomixis, with important implications for our understanding of the evolutionary forces that shape structural variation and diversity in plant reproduction.
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Affiliation(s)
- Daniel Rodriguez-Leal
- Group of Reproductive Development and Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
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