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Ekrt L, Férová A, Koutecký P, Vejvodová K, Hori K, Hornych O. An adventurous journey toward and away from fern apomixis: Insights from genome size and spore abortion patterns. Am J Bot 2024:e16332. [PMID: 38762794 DOI: 10.1002/ajb2.16332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 05/20/2024]
Abstract
PREMISE Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long-term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo-sex hybrid ferns. METHODS We analyzed the genome size of 15 fern species or hybrids ("taxa") via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo-sex hybrid Dryopteris × critica and its 16 apomictically formed offspring. RESULTS Four of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12-451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In Dryopteris × critica, abortion decreased from 93.8% to mean 89.5% in one generation. CONCLUSIONS Our results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the Dryopteris affinis complex.
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Affiliation(s)
- Libor Ekrt
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Alžběta Férová
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Petr Koutecký
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Kateřina Vejvodová
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
| | - Kiyotaka Hori
- The Kochi Prefectural Makino Botanical Garden, Godaisan 4200-6, Kochi, 781-8125, Japan
| | - Ondřej Hornych
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-37005, Czech Republic
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Sochor M, Duchoslav M, Forejtová V, Hroneš M, Konečná M, Trávníček B. Distinct geographic parthenogenesis in spite of niche conservatism and a single ploidy level: A case of Rubus ser. Glandulosi (Rosaceae). New Phytol 2024; 242:1348-1362. [PMID: 38407427 DOI: 10.1111/nph.19618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 02/06/2024] [Indexed: 02/27/2024]
Abstract
Asexual organisms often differ in their geographic distributions from their sexual relatives. This phenomenon, termed geographic parthenogenesis, has long been known, but the underlying factors behind its diverse patterns have been under dispute. Particularly problematic is an association between asexuality and polyploidy in most taxa. Here, we present a new system of geographic parthenogenesis on the tetraploid level, promising new insights into this complex topic. We used flow cytometric seed screen and microsatellite genotyping to characterise the patterns of distribution of sexuals and apomicts and genotypic distributions in Rubus ser. Glandulosi across its range. Ecological modelling and local-scale vegetation and soil analyses were used to test for niche differentiation between the reproductive groups. Apomicts were detected only in North-western Europe, sexuals in the rest of the range in Europe and West Asia, with a sharp borderline stretched across Central Europe. Despite that, we found no significant differences in ecological niches. Genotypic richness distributions suggested independence of the reproductive groups and a secondary contact. We argue that unless a niche differentiation (resulting from polyploidy and/or hybridity) evolves, the main factors behind the patterns of geographic parthenogenesis in plants are phylogeographic history and neutral microevolutionary processes, such as clonal turnover.
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Affiliation(s)
- Michal Sochor
- Centre of the Region Haná for Biotechnological and Agricultural Research, Crop Research Institute, Šlechtitelů 29, Olomouc, 78371, Czech Republic
| | - Martin Duchoslav
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Věra Forejtová
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Station of Apple Breeding for Disease Resistance, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 313, Prague 6-Lysolaje, 16502, Czech Republic
| | - Michal Hroneš
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Michaela Konečná
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Bohumil Trávníček
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
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De Giorgi F, Roscher C, Durka W. Effects of species diversity on trait expression of the clonal herb Taraxacum officinale and its relation to genotype diversity and phenotypic plasticity. Ecol Evol 2024; 14:e11430. [PMID: 38766311 PMCID: PMC11099733 DOI: 10.1002/ece3.11430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/17/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024] Open
Abstract
Plant species respond to varying plant species diversity and associated changes in their abiotic and biotic environment with changes in their phenotype. However, it is not clear to what degree this phenotypic differentiation is due to genotype diversity within populations or phenotypic plasticity of plant individuals. We studied individuals of 16 populations of the clonal herb Taraxacum officinale grown in plant communities of different species richness in a 17-year-old grassland biodiversity experiment (Jena Experiment). We collected 12 individuals in each population to measure phenotypic traits and identify distinct genotypes using microsatellite DNA markers. Plant species richness did not influence population-level genotype and trait diversity. However, it affected the expression of several phenotypic traits, e.g. leaf and inflorescence number, maximum leaf length and seed mass, which increased with increasing plant species richness. Moreover, population-level trait diversity correlated positively with genotype richness for leaf dry matter content (LDMC) and negatively with inflorescence number. For several traits (i.e. seed mass, germination rate, LDMC, specific leaf area (SLA)), a larger portion of variance was explained by genotype identity, while variance in other traits (i.e. number of inflorescences, leaf nitrogen concentration, leaf number, leaf length) resided within genotypes and thus was mostly due to phenotypic plasticity. Overall, our findings show that plant species richness positively affected the population means of some traits related to whole-plant performance, whose variation was achieved through both phenotypic plasticity and genotype composition of a population.
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Affiliation(s)
- Francesca De Giorgi
- Department of Physiological DiversityHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Christiane Roscher
- Department of Physiological DiversityHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Walter Durka
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Department of Community EcologyHelmholtz Centre for Environmental Research – UFZHalleGermany
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Tao L, Tao K, Li Q, Zhang Y, Hu X, Luo Y, Li L. Pollination Syndrome, Florivory, and Breeding System of Satyrium nepalense var. ciliatum (Orchidaceae) in Central Yunnan, China. Plants (Basel) 2024; 13:1228. [PMID: 38732443 PMCID: PMC11085663 DOI: 10.3390/plants13091228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/21/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
Research on Satyrium nepalense var. ciliatum (Lindl.) Hook. f. has primarily focused on populations in Northwestern Yunnan, with limited studies on pollination syndromes and insect behavior. In addition, it is geographically limited in its breeding system studies. Here, pollination syndromes, florivory, and breeding systems of S. nepalense var. ciliatum from Liangwang Mountain (Central Yunnan, China) were investigated through field work, microscope, scanning electron microscope (SEM), and parafin section. It was revealed that the pollination syndrome was possessing out-crossing, such as bright color, a developed rostellum, nectar glands in the spur, and food hairs at the lip base. The color and nectar attracted flower visitors, and florivory was observed. Some flower visitors pollinated their companion species. Ants were identified as floral visitors for the first time in Satyrium, although substantial pollination was not observed. Ants might be potential pollinators. S. nepalense var. ciliatum possessed a mixed breeding system, including selfing, out-crossing, and apomixis, with apomixis being predominant in nature. It is suggested that the pollination syndrome, florivory, and pollination competition would contribute to its mixed breeding systems, particularly leading to the occurrence of apomixis.
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Affiliation(s)
- Lei Tao
- College of Forestry, Southwest Forestry University, Kunming 650224, China; (L.T.); (K.T.); (Y.Z.); (X.H.)
- College of Biological Science and Food Engineering, Southwest Forestry University, Kunming 650224, China;
| | - Kaifeng Tao
- College of Forestry, Southwest Forestry University, Kunming 650224, China; (L.T.); (K.T.); (Y.Z.); (X.H.)
| | - Qingqing Li
- College of Biological Science and Food Engineering, Southwest Forestry University, Kunming 650224, China;
- Kunming Xianghao Technology Co., Ltd., Kunming 650204, China
| | - Yingduo Zhang
- College of Forestry, Southwest Forestry University, Kunming 650224, China; (L.T.); (K.T.); (Y.Z.); (X.H.)
- College of Biological Science and Food Engineering, Southwest Forestry University, Kunming 650224, China;
| | - Xiangke Hu
- College of Forestry, Southwest Forestry University, Kunming 650224, China; (L.T.); (K.T.); (Y.Z.); (X.H.)
| | - Yan Luo
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences & Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
| | - Lu Li
- College of Forestry, Southwest Forestry University, Kunming 650224, China; (L.T.); (K.T.); (Y.Z.); (X.H.)
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Honari M, Ashnest JR, Sharbel TF. Sex- versus apomixis-specific polymorphisms in the 5'UTR of APOLLO from Boechera shift gene expression from somatic to reproductive tissues in Arabidopsis. Front Plant Sci 2024; 15:1308059. [PMID: 38476690 PMCID: PMC10929715 DOI: 10.3389/fpls.2024.1308059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/31/2024] [Indexed: 03/14/2024]
Abstract
Introduction Among candidate genes underlying the control components of apomixis, APOLLO is known for its strong linkage to apomeiosis in the genus Boechera. The gene has "apo alleles," which are characterized by a set of linked apomixis-specific polymorphisms, and "sex alleles." All apomictic Boechera genotypes are heterozygous for the apo/sex alleles, whereas all sexual genotypes are homozygous for sex alleles. Methods In this study, native and synthetic APOLLO promoters were characterized by detecting the expression level of the β-glucuronidase (GUS) gene in Arabidopsis. Results Comparing various flower developmental stages in transgenic lines containing different constructs with 2-kb native transgenic lines revealed that changes to the APOLLO promoter causes shifts in tissue and developmental stage specificity of GUS expression. Importantly, several apomixis-specific polymorphisms in the 5'UTR change the timing and location of GUS activity from somatic to reproductive tissues. Discussion These synthetic data simulate a plausible evolutionary process, whereby apomixis-specific gene activity can be achieved.
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Affiliation(s)
- Maryam Honari
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, SK, Canada
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Bradican JP, Tomasello S, Boscutti F, Karbstein K, Hörandl E. Phylogenomics of Southern European Taxa in the Ranunculus auricomus Species Complex: The Apple Doesn't Fall Far from the Tree. Plants (Basel) 2023; 12:3664. [PMID: 37960021 PMCID: PMC10650656 DOI: 10.3390/plants12213664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 11/15/2023]
Abstract
The taxonomic status of many Southern European taxa of the Ranunculus auricomus complex remains uncertain despite this region's proximity to the native ranges of the sexual progenitor species of the complex. We investigated whether additional sexual progenitor species are present in the Mediterranean region. Utilizing target enrichment of 736 single-copy nuclear gene regions and flow cytometry, we analyzed phylogenomic relationships, the ploidy level, and the reproductive mode in representatives of 16 populations in Southern Europe, with additional sequence data from herbarium collections. Additionally, phased sequence assemblies from suspected nothotaxa were mapped to previously described sexual progenitor species in order to determine hybrid ancestry. We found the majority of Mediterranean taxa to be tetraploid, with hybrid populations propagating primarily via apomixis. Phylogenomic analysis revealed that except for the progenitor species, the Mediterranean taxa are often polyphyletic. Most apomictic taxa showed evidence of mixed heritage from progenitor species, with certain progenitor genotypes having mapped more to the populations from adjacent geographical regions. Geographical trends were found in phylogenetic distance, roughly following an east-to-west longitudinal demarcation of the complex, with apomicts extending to the southern margins. Additionally, we observed post-hybridization divergence between the western and eastern populations of nothotaxa in Southern Europe. Our results support a classification of apomictic populations as nothotaxa, as previously suggested for Central Europe.
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Affiliation(s)
- John Paul Bradican
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
- Georg-August University School of Sciences (GAUSS), University of Göttingen, Wilhelmsplatz 1, 37073 Göttingen, Germany
| | - Salvatore Tomasello
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
| | - Francesco Boscutti
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze 91, 33100 Udine, Italy
| | - Kevin Karbstein
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans Knöll Strasse 10, 07743 Jena, Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany
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Bicknell R, Gaillard M, Catanach A, McGee R, Erasmuson S, Fulton B, Winefield C. Genetic mapping of the LOSS OF PARTHENOGENESIS locus in Pilosella piloselloides and the evolution of apomixis in the Lactuceae. Front Plant Sci 2023; 14:1239191. [PMID: 37692427 PMCID: PMC10485273 DOI: 10.3389/fpls.2023.1239191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/01/2023] [Indexed: 09/12/2023]
Abstract
Pilosella piloselloides var. praealta (syn. P. praealta; Hieracium praealtum) is a versatile model used to study gametophytic apomixis. In this system apomixis is controlled by three loci: one that controls the avoidance of meiosis (LOA), one that controls the avoidance of fertilization (LOP) and a third that controls autonomous endosperm formation (AutE). Using a unique polyhaploid mapping approach the LOP locus was mapped to a 654 kb genomic interval syntenic to linkage group 8 of Lactuca sativa. Polyhaploids form through the gametophytic action of a dominant determinant at LOP, so the mapped region represents both a functional and a physical domain for LOP in P. piloselloides. Allele sequence divergence (ASD) analysis of the PARTHENOGENESIS (PAR) gene within the LOP locus revealed that dominant PAR alleles in Pilosella remain highly similar across the genus, whilst the recessive alleles are more divergent. A previous report noted that dominant PAR alleles in both Pilosella and Taraxacum are modified by the presence of a class II transposable element (TE) in the promoter of the gene. This observation was confirmed and further extended to the related genus Hieracium. Sufficient differences were noted in the structure and location of the TE elements to conclude that TE insertional events had occurred independently in the three genera. Measures of allele crossover amongst the polyhaploids revealed that P. piloselloides is an autopolyploid species with tetrasomic inheritance. It was also noted that the dominant determinant of LOP in P. piloselloides could transmit via a diploid gamete (pollen or egg) but not via a haploid gamete. Using this information, a model is presented of how gametophytic apomixis may have evolved in several members of the Lactuceae, a tribe of the Asteraceae.
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Affiliation(s)
- Ross Bicknell
- Department of Breeding and Genomics, The New Zealand Institute for Plant and Food Research Limited, Christchurch, New Zealand
| | - Marion Gaillard
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
| | - Andrew Catanach
- Department of Breeding and Genomics, The New Zealand Institute for Plant and Food Research Limited, Christchurch, New Zealand
| | - Robert McGee
- Department of Plant Science, McGill University, Lincoln, QC, Canada
| | - Sylvia Erasmuson
- Department of Breeding and Genomics, The New Zealand Institute for Plant and Food Research Limited, Christchurch, New Zealand
| | - Beatrice Fulton
- Department of Breeding and Genomics, The New Zealand Institute for Plant and Food Research Limited, Christchurch, New Zealand
| | - Christopher Winefield
- Department of Wine, Food and Molecular Biosciences, Lincoln University, Canterbury, New Zealand
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Greaves E, Kron P, Husband BC. Demographic and reproductive impacts of hybridization unrelated to hybrid viability in a native plant. Am J Bot 2023; 110:e16208. [PMID: 37409880 DOI: 10.1002/ajb2.16208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 07/07/2023]
Abstract
PREMISE Introduced species can influence native congeners through production of hybrids and introgression, but impacts not involving viable hybrids, such as reduced conspecific offspring and increased asexual seed production, are rarely examined. Here we tested for these demographic and reproductive consequences of hybridization between introduced, domesticated apple (Malus domestica) and native crabapple (M. coronaria) in southern Canada. METHODS We applied four pollination treatments (open, M. coronaria, M. domestica, open + M. coronaria) to focal M. coronaria trees across multiple years and assessed the number and reproductive origins of resulting seeds (hybrid or conspecific endosperm and, for each, sexual or asexual embryo) using flow cytometry. RESULTS In open-pollinated fruit, 27% of seeds had hybrid endosperm; 52% of embryos were asexual. The number of conspecific embryos (sexual or asexual) per fruit did not decline significantly with increasing hybridization, indicating no seed discounting, but hand pollinations using only domestic apple or crabapple pollen reduced the number of conspecific embryos significantly. Hybridization was not associated with a change in percentage asexual embryos, overall, but there was an increase in asexual embryos in tetraploid seeds, the maternal and most common offspring ploidy. CONCLUSIONS We conclude that hybridization can influence native Malus in ways beyond the production of viable hybrids, with significant implications for population dynamics and genetic structure.
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Affiliation(s)
- Elaina Greaves
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
| | - Paul Kron
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
| | - Brian C Husband
- Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1, Canada
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Carra A, Catalano C, Pathirana R, Sajeva M, Inglese P, Motisi A, Carimi F. Increased Zygote-Derived Plantlet Formation through In Vitro Rescue of Immature Embryos of Highly Apomictic Opuntia ficus-indica (Cactaceae). Plants (Basel) 2023; 12:2758. [PMID: 37570913 PMCID: PMC10421068 DOI: 10.3390/plants12152758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/02/2023] [Accepted: 06/09/2023] [Indexed: 08/13/2023]
Abstract
O. ficus-indica (prickly pear cactus) is an important forage and food source in arid and semiarid ecosystems and is the most important cactus species in cultivation globally. The high degree of apomixis in the species is a hindrance in plant breeding programs where genetic segregation is sought for the selection of superior genotypes. To understand if in ovulo embryo rescue could increase the proportion of zygotic seedlings, we compared the mature seed-derived seedlings with those regenerated from in vitro embryo rescue at 20, 25, 30, 35, and 40 post-anthesis days (PADs) in four Italian cultivars. The seedlings were classified as apomictic or zygotic based on molecular marker analysis using inter-sequence single repeat (ISSR) primers. Multiple embryos were recovered from all the cultured immature ovules, and plantlets were regenerated and acclimatized to the field post hardening, with success rates ranging from 62% ('Senza spine') to 83% ('Gialla'). The level of polyembryony differed among cultivars and recovery dates, with the highest being 'Rossa', producing 4.8 embryos/ovule at 35 PADs, and 'Gialla', the lowest, with 2.7 at 40 PADs. The maximum number of embryos observed within a single ovule was 14 in 'Trunzara bianca'. ISSR analysis revealed that ovule culture at 35 PADs produced the highest percentage of zygotic seedlings in all the cultivars, from 51% ('Rossa') to 98% ('Gialla'), with a high genotype effect as well. Mature seeds produced much fewer seedlings per seed, ranging from 1.2 in 'Trunzara bianca' to 2.0 in 'Rossa' and a lower percentage of zygotic seedlings (from 14% in 'Rossa' to 63% in 'Gialla'). Our research opens a pathway to increase the availability of zygotic seedlings in O. ficus-indica breeding programs through in ovulo embryo culture.
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Affiliation(s)
- Angela Carra
- CNR—Istituto di Bioscienze e BioRisorse, Via Ugo La Malfa 153, 90146 Palermo, Italy; (A.C.); (C.C.); (A.M.)
| | - Caterina Catalano
- CNR—Istituto di Bioscienze e BioRisorse, Via Ugo La Malfa 153, 90146 Palermo, Italy; (A.C.); (C.C.); (A.M.)
| | - Ranjith Pathirana
- Plant & Food Research Australia Pty Ltd., #46 Plant Breeding, Waite Road, Urrbrae, SA 5064, Australia;
- School of Agriculture, Food and Wine, University of Adelaide, Waite Road, Urrbrae, SA 5064, Australia
| | - Maurizio Sajeva
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 18, 90123 Palermo, Italy;
| | - Paolo Inglese
- Department of Agricultural Food and Forest Sciences, University of Palermo, Viale delle Scienze, 90128 Palermo, Italy;
| | - Antonio Motisi
- CNR—Istituto di Bioscienze e BioRisorse, Via Ugo La Malfa 153, 90146 Palermo, Italy; (A.C.); (C.C.); (A.M.)
| | - Francesco Carimi
- CNR—Istituto di Bioscienze e BioRisorse, Via Ugo La Malfa 153, 90146 Palermo, Italy; (A.C.); (C.C.); (A.M.)
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Zhuzhzhalova TP, Nalbandyan AA, Vasilchenko EN, Cherkasova NN. Morphogenetic peculiarities of reproductive biology in sugar beet (Beta vulgaris L.) breeding. Vavilovskii Zhurnal Genet Selektsii 2023; 27:207-217. [PMID: 37287806 PMCID: PMC10242388 DOI: 10.18699/vjgb-23-27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 06/09/2023] Open
Abstract
This review considers the processes of morphogenesis used in the development of propagation methods and the creation of a new starting material for sugar beet. It has been demonstrated that methods of particulation, in vitro microcloning and cell breeding that reflect non-sexual forms of plant reproduction increase the effectiveness of breeding experiments. The review describes the in vitro culture methods maintaing a tendency in plants for vegetative propagation and stimulating increase in genetic variability of properties when mutagens such as ethyl methanesulfonate, alien genetic structures with mf2 and mf3 bacterial genes in Agrobacterium tumefaciens strains, and selective agents (Сd++ ions and abscisic acid) are incorporated into plant cells. It presents the results of using fluorescent microscopy, cytophotometry, biochemical analysis and determining the level of phytohormones and content of nucleic acids in nuclei for forecasting the seed setting ability. It has demonstrated that long self-pollination of plants causes decrease in fertility of pollen grains, resulting in the sterilization of male gametes and the appearance of pistillody flowers. Self-fertile plants isolated from these lines serve as sterility fixers, while the apomixis elements increased the ovule number, additional embryo sacs and embryos. A role of apomixis in contributing to variability in the onto- and phylogenetic development of plants have been substantiated. The review reflects the morphological features of the in vitro development of sexual and somatic cells in embryos during the formation of seedlings based on floral and vegetative embryoidogeny. Use of the SNP and SSR (Unigenes) molecular-genetic markers having a high polymorphism level has appeared effective to characterize the developed breeding material and hybrid components when carrying out crossings. The study of sugar beet starting materials for the presence of TRs mini-satellite loci making it possible to reveal O-type plants-pollinators (sterility fixing agent) and MS-form plants are of interest for breeding as well. The selected material can be widely used in breeding to produce hybrids, allowing for a 2-3- fold reduction of the development period. The review also discusses the prospects for the development and implementation of new methods and original schemes in sugar beet genetics, biotechnology and breeding.
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Affiliation(s)
- T P Zhuzhzhalova
- The A.L. Mazlumov All-Russian Research Institute of Sugar Beet and Sugar, vil. VNIISS, Ramonsky district, Voronezh region, Russia
| | - A A Nalbandyan
- The A.L. Mazlumov All-Russian Research Institute of Sugar Beet and Sugar, vil. VNIISS, Ramonsky district, Voronezh region, Russia
| | - E N Vasilchenko
- The A.L. Mazlumov All-Russian Research Institute of Sugar Beet and Sugar, vil. VNIISS, Ramonsky district, Voronezh region, Russia
| | - N N Cherkasova
- The A.L. Mazlumov All-Russian Research Institute of Sugar Beet and Sugar, vil. VNIISS, Ramonsky district, Voronezh region, Russia
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11
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Caperta AD, Fernandes I, Conceição SIR, Marques I, Róis AS, Paulo OS. Ovule Transcriptome Analysis Discloses Deregulation of Genes and Pathways in Sexual and Apomictic Limonium Species (Plumbaginaceae). Genes (Basel) 2023; 14:genes14040901. [PMID: 37107659 PMCID: PMC10137852 DOI: 10.3390/genes14040901] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
The genus Limonium Mill. (sea lavenders) includes species with sexual and apomixis reproductive strategies, although the genes involved in these processes are unknown. To explore the mechanisms beyond these reproduction modes, transcriptome profiling of sexual, male sterile, and facultative apomictic species was carried out using ovules from different developmental stages. In total, 15,166 unigenes were found to be differentially expressed with apomictic vs. sexual reproduction, of which 4275 were uniquely annotated using an Arabidopsis thaliana database, with different regulations according to each stage and/or species compared. Gene ontology (GO) enrichment analysis indicated that genes related to tubulin, actin, the ubiquitin degradation process, reactive oxygen species scavenging, hormone signaling such as the ethylene signaling pathway and gibberellic acid-dependent signal, and transcription factors were found among differentially expressed genes (DEGs) between apomictic and sexual plants. We found that 24% of uniquely annotated DEGs were likely to be implicated in flower development, male sterility, pollen formation, pollen-stigma interactions, and pollen tube formation. The present study identifies candidate genes that are highly associated with distinct reproductive modes and sheds light on the molecular mechanisms of apomixis expression in Limonium sp.
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Affiliation(s)
- Ana D Caperta
- Linking Landscape, Environment, Agriculture and Food (LEAF), Research Center, Associate Laboratory TERRA, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Isabel Fernandes
- cE3c-Centre for Ecology, Evolution and Environmental Changes, CHANGE-Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Sofia I R Conceição
- Linking Landscape, Environment, Agriculture and Food (LEAF), Research Center, Associate Laboratory TERRA, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
- LASIGE Computer Science and Engineering Research Centre, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Isabel Marques
- Linking Landscape, Environment, Agriculture and Food (LEAF), Research Center, Associate Laboratory TERRA, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
- Forest Research Centre (CEF), Associate Laboratory TERRA, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Ana S Róis
- Linking Landscape, Environment, Agriculture and Food (LEAF), Research Center, Associate Laboratory TERRA, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
- School of Psychology and Life Sciences, Universidade Lusófona de Humanidades e Tecnologias (ULHT), Campo Grande 376, 1749-024 Lisboa, Portugal
| | - Octávio S Paulo
- cE3c-Centre for Ecology, Evolution and Environmental Changes, CHANGE-Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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12
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Neiman M, Sharbrough J. A tale of two genomes: What drives mitonuclear discordance in asexual lineages of a freshwater snail? Bioessays 2023; 45:e2200234. [PMID: 37026407 DOI: 10.1002/bies.202200234] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023]
Abstract
We use genomic information to tell us stories of evolutionary origins. But what does it mean when different genomes report wildly different accounts of lineage history? This genomic "discordance" can be a consequence of a fascinating suite of natural history and evolutionary phenomena, from the different inheritance mechanisms of nuclear versus cytoplasmic (mitochondrial and plastid) genomes to hybridization and introgression to horizontal transfer. Here, we explore how we can use these distinct genomic stories to provide new insights into the maintenance of sexual reproduction, one of the most important unanswered questions in biology. We focus on the strikingly distinct nuclear versus mitochondrial versions of the story surrounding the origin and maintenance of asexual lineages in Potamopyrgus antipodarum, a New Zealand freshwater snail. While key questions remain unresolved, these data inspire multiple testable hypotheses that can be powerfully applied across a broad range of taxa toward a deeper understanding of the causes and consequences of mitonuclear discordance, the maintenance of sex, and the origin of new asexual lineages.
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Affiliation(s)
- Maurine Neiman
- Department of Biology, Department of Gender, Women's, and Sexuality Studies, University of Iowa, Iowa City, Iowa, USA
| | - Joel Sharbrough
- Department of Biology, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
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Montalt R, Cuenca J, Vives MC, Mournet P, Navarro L, Ollitrault P, Aleza P. Genotyping by Sequencing for SNP-Based Linkage Analysis and the Development of KASPar Markers for Male Sterility and Polyembryony in Citrus. Plants (Basel) 2023; 12:1567. [PMID: 37050193 PMCID: PMC10096700 DOI: 10.3390/plants12071567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/29/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Polyembryony and male sterility (MS) are essential characters for citrus breeding. MS, coupled with parthenocarpy, allows for addressing the diversification of diploid seedless mandarin varieties, and nucleocytoplasmic MS is the most prevalent system. Polyembryony limits the use of seed parents in scion breeding programs, and the recovery of monoembryonic hybrids to be used as female parents is a crucial pre-breeding component. The objectives of this work were the identification of SNPs closely linked with the genes implied in these traits for marker-assisted selection. Genotyping by sequencing was used to genotype 61 diploid hybrids from an F1 progeny recovered from crossing 'Kiyomi' and 'Murcott' tangors. A total of 6444 segregating markers were identified and used to establish the two parental genetic maps. They consisted of 1374 and 697 markers encompassing 1416.287 and 1339.735 cM for 'Kiyomi' and 'Murcott', respectively. Phenotyping for MS and polyembryony was performed. The genotype-trait association study identified a genomic region on LG8 which was significantly associated with MS, and a genomic region on LG1 which was significantly associated with polyembryony. Annotation of the identified region for MS revealed 19 candidate genes. One SNP KASPar marker was developed and fully validated for each trait.
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Affiliation(s)
- Rafael Montalt
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113 Valencia, Spain
| | - José Cuenca
- Agrupación de Viveristas de Agrios (AVASA), 12570 Castellón, Spain
| | - María Carmen Vives
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113 Valencia, Spain
| | - Pierre Mournet
- UMR AGAP, CIRAD, 34398 Montpellier, France
- UMR AGAP, Institut Agro, CIRAD, INRAE, Université Montpellier, 34060 Montpellier, France
| | - Luis Navarro
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113 Valencia, Spain
| | - Patrick Ollitrault
- UMR AGAP, CIRAD, 34398 Montpellier, France
- UMR AGAP, Institut Agro, CIRAD, INRAE, Université Montpellier, 34060 Montpellier, France
| | - Pablo Aleza
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113 Valencia, Spain
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Hersh EW, Medina ARL, Whitton J. Dispersal and establishment traits provide a colonization advantage for a polyploid apomictic plant. Am J Bot 2023; 110:e16149. [PMID: 36857315 DOI: 10.1002/ajb2.16149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 05/11/2023]
Abstract
PREMISE Apomictic plants (reproducing asexually through seed) often have larger ranges and occur at higher latitudes than closely related sexuals, a pattern known as geographical parthenogenesis (GP). Explanations for GP include differences in colonizing ability due to reproductive assurance and direct/indirect effects of polyploidy (most apomicts are polyploid) on ecological tolerances. While life history traits associated with dispersal and establishment also contribute to the potential for range expansion, few studies compare these traits in related apomicts and sexuals. METHODS We investigated differences in early life history traits between diploid-sexual and polyploid-apomictic Townsendia hookeri (Asteraceae), which displays a classic pattern of GP. Using lab and greenhouse experiments, we measured seed dispersal traits, germination success, and seedling size and survival in sexual and apomictic populations from across the range of the species. RESULTS While theory predicts that trade-offs between dispersal and establishment traits should be common, this was largely not the case in T. hookeri. Apomictic seeds had both lower terminal velocity (staying aloft longer when dropped) and higher germination success than sexual seeds. While there were no differences in seedling size between reproductive types, apomicts did, however, have slightly lower seedling survival than sexuals. CONCLUSIONS These differences in early life history traits, combined with reproductive assurance conferred by apomixis, suggest that apomicts achieve a greater range through advantages in their ability to both spread and establish.
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Affiliation(s)
- Evan Whitney Hersh
- Department of Botany and Biodiversity Research Centre, The University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada, V6T 1Z4
| | - Alberto Ruiz-Larrea Medina
- Department of Botany and Biodiversity Research Centre, The University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada, V6T 1Z4
| | - Jeannette Whitton
- Department of Botany and Biodiversity Research Centre, The University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada, V6T 1Z4
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Carballo J, Bellido AM, Selva JP, Zappacosta D, Gallo CA, Albertini E, Caccamo M, Echenique V. From tetraploid to diploid, a pangenomic approach to identify genes lost during synthetic diploidization of Eragrostis curvula. Front Plant Sci 2023; 14:1133986. [PMID: 36993842 PMCID: PMC10040859 DOI: 10.3389/fpls.2023.1133986] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 02/24/2023] [Indexed: 06/19/2023]
Abstract
INTRODUCTION In Eragrostis curvula, commonly known as weeping lovegrass, a synthetic diploidization event of the facultative apomictic tetraploid Tanganyika INTA cv. originated from the sexual diploid Victoria cv. Apomixis is an asexual reproduction by seeds in which the progeny is genetically identical to the maternal plant. METHODS To assess the genomic changes related to ploidy and to the reproductive mode occurring during diploidization, a mapping approach was followed to obtain the first E. curvula pangenome assembly. In this way, gDNA of Tanganyika INTA was extracted and sequenced in 2x250 Illumina pair-end reads and mapped against the Victoria genome assembly. The unmapped reads were used for variant calling, while the mapped reads were assembled using Masurca software. RESULTS The length of the assembly was 28,982,419 bp distributed in 18,032 contigs, and the variable genes annotated in these contigs rendered 3,952 gene models. Functional annotation of the genes showed that the reproductive pathway was differentially enriched. PCR amplification in gDNA and cDNA of Tanganyika INTA and Victoria was conducted to validate the presence/absence variation in five genes related to reproduction and ploidy. The polyploid nature of the Tanganyika INTA genome was also evaluated through the variant calling analysis showing the single nucleotide polymorphism (SNP) coverage and allele frequency distribution with a segmental allotetraploid pairing behavior. DISCUSSION The results presented here suggest that the genes were lost in Tanganyika INTA during the diploidization process that was conducted to suppress the apomictic pathway, affecting severely the fertility of Victoria cv.
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Affiliation(s)
- Jose Carballo
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Andrés Martin Bellido
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Juan Pablo Selva
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Diego Zappacosta
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Cristian Andres Gallo
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Emidio Albertini
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy
| | | | - Viviana Echenique
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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Liu DD, Wang DR, Yang XY, Zhao CH, Li SH, Sha GL, Zhang RF, Ge HJ, Tong XS, You CX. Apomictic Malus plants exhibit abnormal pollen development. Front Plant Sci 2023; 14:1065032. [PMID: 36890893 PMCID: PMC9986266 DOI: 10.3389/fpls.2023.1065032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Apomixis is the asexual reproduction through seeds that leads to the production of genetically uniform progeny. It has become an important tool in plant breeding because it facilitates the retention of genotypes with desirable traits and allows seeds to be obtained directly from mother plants. Apomixis is rare in most economically important crops, but it occurs in some Malus species. Here, the apomictic characteristics of Malus were examined using four apomictic and two sexually reproducing Malus plants. Results from transcriptome analysis showed that plant hormone signal transduction was the main factor affecting apomictic reproductive development. Four of the apomictic Malus plants examined were triploid, and pollen was either absent or present in very low densities in the stamen. Variation in the presence of pollen was associated with variation in the apomictic percentage; specifically, pollen was absent in the stamens of tea crabapple plants with the highest apomictic percentage. Furthermore, pollen mother cells failed to progress normally into meiosis and pollen mitosis, a trait mostly observed in apomictic Malus plants. The expression levels of meiosis-related genes were upregulated in apomictic plants. Our findings indicate that our simple method of detecting pollen abortion could be used to identify apple plants that are capable of apomictic reproduction.
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Affiliation(s)
- Dan-Dan Liu
- College of Agriculture, Yunnan University, Kunming, Yunnan, China
| | - Da-Ru Wang
- National Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
| | - Xuan-Yu Yang
- College of Agriculture, Yunnan University, Kunming, Yunnan, China
| | - Chang-Hui Zhao
- College of Agriculture, Yunnan University, Kunming, Yunnan, China
| | - Shao-Hua Li
- College of Agriculture, Yunnan University, Kunming, Yunnan, China
| | - Guang-Li Sha
- Qingdao Academy of Agricultural Sciences, Qingdao, Shandong, China
| | - Rui-Fen Zhang
- Qingdao Academy of Agricultural Sciences, Qingdao, Shandong, China
| | - Hong-Juan Ge
- Qingdao Academy of Agricultural Sciences, Qingdao, Shandong, China
| | - Xian-Song Tong
- Fu-ning Popularizing Agricultural Techniques Center, Fu-ning, Yunnan, China
| | - Chun-Xiang You
- National Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China
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Barcaccia G, Mazzucato A, Albertini E, Zenoni S, Baldoni L, Mousavi S, Mendes MA, Coimbra S, Granell A, Pupilli F. Editorial: Genetics and genomics of plant reproduction for crop breeding, volume II. Front Plant Sci 2023; 14:1145208. [PMID: 36866376 PMCID: PMC9972970 DOI: 10.3389/fpls.2023.1145208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Gianni Barcaccia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Padova, Italy
| | - Andrea Mazzucato
- Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, Viterbo, Italy
| | - Emidio Albertini
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Perugia, Italy
| | - Sara Zenoni
- Department of Biotechnologies, University of Verona, Verona, Italy
| | - Luciana Baldoni
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), Perugia, Italy
| | - Soraya Mousavi
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), Perugia, Italy
| | | | - Silvia Coimbra
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Antonio Granell
- Institute of Molecular and Cellular Biology of Plants, Spanish National Research Council (CSIC), Polytechnic University of Valencia, Valencia, Spain
| | - Fulvio Pupilli
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), Perugia, Italy
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Hörandl E. Geographical Parthenogenesis in Alpine and Arctic Plants. Plants (Basel) 2023; 12:844. [PMID: 36840192 PMCID: PMC9959270 DOI: 10.3390/plants12040844] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The term "Geographical parthenogenesis" describes the phenomenon that asexual organisms usually occupy larger and more northern distribution areas than their sexual relatives, and tend to colonize previously glaciated areas. Several case studies on alpine and arctic plants confirm the geographical pattern, but the causal factors behind the phenomenon are still unclear. Research of the last decade in several plant families has shed light on the question and evaluated some of the classical evolutionary theories. Results confirmed, in general, that the advantages of uniparental reproduction enable apomictic plants to re-colonize faster in larger and more northern distribution areas. Associated factors like polyploidy seem to contribute mainly to the spatial separation of sexual and asexual cytotypes. Ecological studies suggest a better tolerance of apomicts to colder climates and temperate extremes, whereby epigenetic flexibility and phenotypic plasticity play an important role in occupying ecological niches under harsh conditions. Genotypic diversity appears to be of lesser importance for the distributional success of asexual plants. Classical evolutionary theories like a reduced pressure of biotic interactions in colder climates and hence an advantage to asexuals (Red Queen hypothesis) did not gain support from studies on plants. However, it is also still enigmatic why sexual outcrossing remains the predominant mode of reproduction also in alpine floras. Constraints for the origin of apomixis might play a role. Interestingly, some studies suggest an association of sexuality with abiotic stresses. Light stress in high elevations might explain why most alpine plants retain sexual reproduction despite other environmental factors that would favor apomixis. Directions for future research will be given.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, 37073 Göttingen, Germany
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Tomaszewska P, Vorontsova MS, Renvoize SA, Ficinski SZ, Tohme J, Schwarzacher T, Castiblanco V, de Vega JJ, Mitchell RAC, Heslop-Harrison JS(P. Complex polyploid and hybrid species in an apomictic and sexual tropical forage grass group: genomic composition and evolution in Urochloa (Brachiaria) species. Ann Bot 2023; 131:87-108. [PMID: 34874999 PMCID: PMC9904353 DOI: 10.1093/aob/mcab147] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/06/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Diploid and polyploid Urochloa (including Brachiaria, Panicum and Megathyrsus species) C4 tropical forage grasses originating from Africa are important for food security and the environment, often being planted in marginal lands worldwide. We aimed to characterize the nature of their genomes, the repetitive DNA and the genome composition of polyploids, leading to a model of the evolutionary pathways within the group including many apomictic species. METHODS Some 362 forage grass accessions from international germplasm collections were studied, and ploidy was determined using an optimized flow cytometry method. Whole-genome survey sequencing and molecular cytogenetic analysis were used to identify chromosomes and genomes in Urochloa accessions belonging to the 'brizantha' and 'humidicola' agamic complexes and U. maxima. KEY RESULTS Genome structures are complex and variable, with multiple ploidies and genome compositions within the species, and no clear geographical patterns. Sequence analysis of nine diploid and polyploid accessions enabled identification of abundant genome-specific repetitive DNA motifs. In situ hybridization with a combination of repetitive DNA and genomic DNA probes identified evolutionary divergence and allowed us to discriminate the different genomes present in polyploids. CONCLUSIONS We suggest a new coherent nomenclature for the genomes present. We develop a model of evolution at the whole-genome level in diploid and polyploid accessions showing processes of grass evolution. We support the retention of narrow species concepts for Urochloa brizantha, U. decumbens and U. ruziziensis, and do not consider diploids and polyploids of single species as cytotypes. The results and model will be valuable in making rational choices of parents for new hybrids, assist in use of the germplasm for breeding and selection of Urochloa with improved sustainability and agronomic potential, and assist in measuring and conserving biodiversity in grasslands.
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Affiliation(s)
| | | | | | | | - Joseph Tohme
- International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia
| | - Trude Schwarzacher
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | | | | | | | - J S (Pat) Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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20
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Kolarčik V, Mirková M, Mikoláš V. Reproduction Modes and Conservation Implications in Three Polyploid Sorbus Stenoendemics in Eastern Slovakia (Central Europe). Plants (Basel) 2023; 12:373. [PMID: 36679086 PMCID: PMC9863969 DOI: 10.3390/plants12020373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
The remarkable species diversity of the genus Sorbus is a result of polyploidization and frequent hybridization between interacting species of different cytotypes. Moreover, hybridization is possible between several parental taxa. Gametophytic apomixis, which is common among polyploid Sorbus taxa, indicates the role of clonal reproduction in the evolutionary stabilization of hybridogeneous genotypes. The precise determination of the origin of seeds and their quantitative evaluation may elucidate inter-cytotype interactions, the potential role of mixed-cytotype populations in evolutionary success, and the long-term survival of some hybrid species. We investigated the reproduction modes of selected species of Sorbus in mixed-cytotype populations in eastern Slovakia, Central Europe. We determined the pollen quality, seed production rate, and the ploidy level of mature trees, as well as the origin of the embryo and endosperm in seeds of the stenoendemics S. amici-petri, S. dolomiticola, and S. hornadensis. The tetraploids S. amici-petri and S. hornadensis are characterized by regular and highly stainable pollen grains and reproduce predominantly via pseudogamous apomixis. In contrast, triploid S. dolomiticola usually has oval, heterogenous, and weakly stainable pollen grains, suggesting male meiotic irregularities. Although seeds originate via pseudogamous apomixis in S. dolomiticola as well, the ploidy level of sperm cells participating in the fertilization of central cells is usually determined by co-occurring species of different cytotypes. This suggests that maintaining mating partners is necessary for the long-term survival of a triploid species. We documented rare BIII hybrids and the residual sexuality in tetraploids. The distribution of seeds of meiotic and apomeiotic origins in S. amici-petri shows bimodal characteristics; however, genotypes with predominantly sexual seed types are rare. Reproduction modes documented in polyploid stenoendemics of Sorbus and inferred microevolutionary intercytotype relationships highlight the mixed-cytotype populations as the source of biodiversity in apomictic plant complexes. We suggest that conservation efforts should focus on maintaining the species and cytotypic diversity of Sorbus populations, especially when it comes to the conservation of triploid species.
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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
| | - Mária Mirková
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, Slovakia
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Nokkala S, Kuznetsova VG, Pietarinen P, Nokkala C. Evolutionary Potential of Parthenogenesis-Bisexual Lineages within Triploid Apomictic Thelytoky in Cacopsylla ledi (Flor, 1861) (Hemiptera, Psylloidea) in Fennoscandia. Insects 2022; 13:1140. [PMID: 36555050 PMCID: PMC9781518 DOI: 10.3390/insects13121140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/29/2022] [Accepted: 12/08/2022] [Indexed: 06/17/2023]
Abstract
A widely accepted hypothesis is that parthenogenesis is an evolutionary dead end since it is selectively advantageous in the short term only but results in lowered diversification rates. Triploid apomictic parthenogenesis might represent an exception, as in favorable environments, triploid females are able to produce rare males and diploid females. The aim of the present study was to analyze the modes of reproduction and their evolutionary implications in the parthenogenetic psyllid Cacopsylla ledi (Flor, 1861) from Fennoscandia. The cytogenetic assessment of ploidy levels and the analysis of the COI haplotype revealed two geographically separated bisexual lineages implying genuine bisexual populations. The southern lineage occurring south of latitude 65° N in Finland showed a COI haplotype different from that of parthenogenetic triploids in the same population but identical to the haplotype of specimens in a genuine bisexual population in the Czech Republic. This allows us to suggest that bisexuals in southern Fennoscandia represent the original bisexual C. ledi. By contrast, in the northern bisexual lineage north of latitude 65° N, rare males and diploid females carried the same haplotype as triploids in the same population, having been produced by the triploids. In the Kola Peninsula, a genuine bisexual population of presumably rare male/diploid female origin was discovered. As this population is geographically isolated from populations of the ancestral bisexual C. ledi, it can develop into a new bisexual species through peripatric speciation during evolution. Our findings demonstrate that apomictic triploid parthenogenesis is not necessarily an evolutionary dead end but is able to lead to the emergence of a new bisexual species of parthenogenetic origin.
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Affiliation(s)
- Seppo Nokkala
- Laboratory of Genetics, Department of Biology, University of Turku, FI-20014 Turku, Finland
| | - Valentina G. Kuznetsova
- Department of Karyosystematics, Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, 199034 Saint-Petersburg, Russia
| | - Peppi Pietarinen
- Laboratory of Genetics, Department of Biology, University of Turku, FI-20014 Turku, Finland
| | - Christina Nokkala
- Laboratory of Genetics, Department of Biology, University of Turku, FI-20014 Turku, Finland
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22
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Tang N, Cao Z, Wu P, Zhang X, Lou J, Liu Y, Wang Q, Hu Y, Si S, Sun X, Chen Z. Genome-wide identification, interaction of the MADS-box proteins in Zanthoxylum armatum and functional characterization of ZaMADS80 in floral development. Front Plant Sci 2022; 13:1038828. [PMID: 36507394 PMCID: PMC9732391 DOI: 10.3389/fpls.2022.1038828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
As a typical dioecious species, Zanthoxylum armatum establishes apomictic reproduction, hence only female trees are cultivated. However, male and hermaphrodite flowers have recently appeared in female plants, resulting in a dramatic yield reduction. To date, the genetic basis underlying sex determination and apomixis in Z. armatum has been largely unknown. Here, we observed abortion of the stamen or carpel prior to primordium initiation, thus corroborating the potential regulation of MADS-box in sex determination. In Z. armatum, a total of 105 MADS-box genes were identified, harboring 86 MIKC-type MADSs with lack of FLC orthologues. Transcriptome analysis revealed candidate MADSs involved in floral organ identity, including ten male-biased MADSs, represented by ZaMADS92/81/75(AP3/PI-like), and twenty-six female-specified, represented by ZaMADS80/49 (STK/AGL11-like) and ZaMADS42 (AG-like). Overexpressing ZaMADS92 resulted in earlier flowering, while ZaMADS80 overexpression triggered precocious fruit set and parthenocarpy as well as dramatic modifications in floral organs. To characterize their regulatory mechanisms, a comprehensive protein-protein interaction network of the represented MADSs was constructed based on yeast two-hybrid and bimolecular fluorescence complementation assays. Compared with model plants, the protein interaction patterns in Z. armatum exhibited both conservation and divergence. ZaMADS70 (SEP3-like) interacted with ZaMADS42 and ZaMADS48 (AP3-like) but not ZaMADS40 (AP1-like), facilitating the loss of petals in Z. armatum. The ZaMADS92/ZaMADS40 heterodimer could be responsible for accelerating flowering in ZaMADS92-OX lines. Moreover, the interactions between ZaMADS80 and ZaMADS67(AGL32-like) might contribute to apomixis. This work provides new insight into the molecular mechanisms of MADS-boxes in sex organ identity in Z. armatum.
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Affiliation(s)
- Ning Tang
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Zhengyan Cao
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
- College of Horticulture and Gardening, Yangtze University, Jingzhou, China
| | - Peiyin Wu
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
- College of Horticulture and Gardening, Yangtze University, Jingzhou, China
| | - Xian Zhang
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Juan Lou
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Yanni Liu
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
- College of Biology and Food Engineering, Chongqing Three Georges University, Chongqing, China
| | - Qiyao Wang
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Yang Hu
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Shuo Si
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Xiaofan Sun
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
| | - Zexiong Chen
- Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing, China
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23
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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. Front Plant Sci 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Higgins J, Tomaszewska P, Pellny TK, Castiblanco V, Arango J, Tohme J, Schwarzacher T, Mitchell RA, Heslop-Harrison JS, De Vega JJ. Diverged subpopulations in tropical Urochloa (Brachiaria) forage species indicate a role for facultative apomixis and varying ploidy in their population structure and evolution. Ann Bot 2022; 130:657-669. [PMID: 36112370 PMCID: PMC9670755 DOI: 10.1093/aob/mcac115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/13/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Urochloa (syn. Brachiaria) is a genus of tropical grasses sown as forage feedstock, particularly in marginal soils. Here we aimed to clarify the genetic diversity and population structure in Urochloa species to understand better how population evolution relates to ploidy level and occurrence of apomictic reproduction. METHODS We explored the genetic diversity of 111 accessions from the five Urochloa species used to develop commercial cultivars. These accessions were conserved from wild materials collected at their centre of origin in Africa, and they tentatively represent the complete Urochloa gene pool used in breeding programmes. We used RNA-sequencing to generate 1.1 million single nucleotide polymorphism loci. We employed genetic admixture, principal component and phylogenetic analyses to define subpopulations. RESULTS We observed three highly differentiated subpopulations in U. brizantha, which were unrelated to ploidy: one intermixed with U. decumbens, and two diverged from the former and the other species in the complex. We also observed two subpopulations in U. humidicola, unrelated to ploidy; one subpopulation had fewer accessions but included the only characterized sexual accession in the species. Our results also supported a division of U. decumbens between diploids and polyploids, and no subpopulations within U. ruziziensis and U. maxima. CONCLUSIONS Polyploid U. decumbens are more closely related to polyploid U. brizantha than to diploid U. decumbens, which supports the divergence of both polyploid groups from a common tetraploid ancestor and provides evidence for the hybridization barrier of ploidy. The three differentiated subpopulations of apomictic polyploid U. brizantha accessions constitute diverged ecotypes, which can probably be utilized in hybrid breeding. Subpopulations were not observed in non-apomictic U. ruziziensis. Sexual Urochloa polyploids were not found (U. brizantha, U. decumbens) or were limited to small subpopulations (U. humidicola). The subpopulation structure observed in the Urochloa sexual-apomictic multiploidy complexes supports geographical parthenogenesis, where the polyploid genotypes exploit the evolutionary advantage of apomixis, i.e. uniparental reproduction and clonality, to occupy extensive geographical areas.
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Affiliation(s)
- J Higgins
- Earlham Institute, Norwich Research Park, Norwich NR4 7UZ, UK
| | - P Tomaszewska
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - T K Pellny
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - V Castiblanco
- International Center for Tropical Agriculture (CIAT), 6713 Cali, Colombia
| | - J Arango
- International Center for Tropical Agriculture (CIAT), 6713 Cali, Colombia
| | - J Tohme
- International Center for Tropical Agriculture (CIAT), 6713 Cali, Colombia
| | - T Schwarzacher
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - R A Mitchell
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - J S Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization/Guangdong Provincial, Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
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Rushworth CA, Wagner MR, Mitchell-Olds T, Anderson JT. The Boechera model system for evolutionary ecology. Am J Bot 2022; 109:1939-1961. [PMID: 36371714 DOI: 10.1002/ajb2.16090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 06/16/2023]
Abstract
Model systems in biology expand the research capacity of individuals and the community. Closely related to Arabidopsis, the genus Boechera has emerged as an important ecological model owing to the ability to integrate across molecular, functional, and eco-evolutionary approaches. Boechera species are broadly distributed in relatively undisturbed habitats predominantly in western North America and provide one of the few experimental systems for identification of ecologically important genes through genome-wide association studies and investigations of selection with plants in their native habitats. The ecologically, evolutionarily, and agriculturally important trait of apomixis (asexual reproduction via seeds) is common in the genus, and field experiments suggest that abiotic and biotic environments shape the evolution of sex. To date, population genetic studies have focused on the widespread species B. stricta, detailing population divergence and demographic history. Molecular and ecological studies show that balancing selection maintains genetic variation in ~10% of the genome, and ecological trade-offs contribute to complex trait variation for herbivore resistance, flowering phenology, and drought tolerance. Microbiome analyses have shown that host genotypes influence leaf and root microbiome composition, and the soil microbiome influences flowering phenology and natural selection. Furthermore, Boechera offers numerous opportunities for investigating biological responses to global change. In B. stricta, climate change has induced a shift of >2 weeks in the timing of first flowering since the 1970s, altered patterns of natural selection, generated maladaptation in previously locally-adapted populations, and disrupted life history trade-offs. Here we review resources and results for this eco-evolutionary model system and discuss future research directions.
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Affiliation(s)
| | - Maggie R Wagner
- Department of Ecology and Evolutionary Biology, Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, KS, 66045, USA
| | | | - Jill T Anderson
- Department of Genetics and Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
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26
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Guo H, Qi X, Li T, Fan Y, Huo H, Yu Q, Zeng F. Editorial: Molecular basis of asexual reproduction and its application in crops. Front Plant Sci 2022; 13:1033212. [PMID: 36267937 PMCID: PMC9578510 DOI: 10.3389/fpls.2022.1033212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Huihui Guo
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai’an, China
| | - Xiushan Qi
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai’an, China
| | - Tongtong Li
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai’an, China
| | - Yijie Fan
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai’an, China
| | - Heqiang Huo
- Department of Environmental Horticulture, University of Florida, Apopka, FL, United States
| | - Qingyi Yu
- Texas A&M AgriLife Research, Texas A&M University, Dallas, TX, United States
| | - Fanchang Zeng
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai’an, China
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27
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Xia Y, Wang Y, Hu Y, Zhan Y, Dan J, Tang N, Tian J, Cao M. Double-seedlings and embryo-free seeds generated by genetic engineering. Front Plant Sci 2022; 13:999031. [PMID: 36262658 PMCID: PMC9576183 DOI: 10.3389/fpls.2022.999031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Apomixis can fix the heterosis of Hybrid F1, by maintaining its heterozygous genotype, and is an ideal way for the development of hybrid rice. In this paper, we designed an engineering strategy for realizing apomictic reproduction of hybrid rice in the way of induce adventitious embryos. An embryogenesis gene, AtWUS, controlled by the ovule-specific promoter, a ribonuclease gene Barnase driven by the egg cell-specific promoter pDD45, and an inactivation gene ZmAA1 driven by the pollen-specific promoter pG47 were simultaneously integrated into one T-DNA, and co-transformed with the second T-DNA carrying a Barstar gene. Double-seedlings were observed in transgenic line. Whole-genome sequencing and ploidy levels confirmed by flow cytometry showed that one of the double-seedlings was heterozygous diploid and the other seedling was homozygous haploid, which confirmed that embryogenesis in one of the double-seedlings arises from the zygote after fertilization and the other derived from an unfertilized gamete. Meanwhile we obtained embryo-free seeds at frequencies of 2.6% to 3.8% in T1 generation, and 0.75% to 3% in T2 generation. Though we did not obtained adventitious embryos in hybrid rice in this study, the phenomenon of double-seedlings and embryo-free seeds in transgenic line was informative and strongly suggested that endosperm development is an autonomously organized process in rice, independent of egg cell fertilization and embryo-endosperm communication. This provides novel insights into the induction of haploid embryos and lends theoretical support to successful clonal propagation using synthetic apomixis.
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Affiliation(s)
- Yumei Xia
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
- National Center of Technology Innovation for Saline-Alkali Tolerant Rice in Sanya, Sanya, China
| | - Yao Wang
- Long Ping Branch, Graduate School of Hunan University, Changsha, China
| | - Yuanyi Hu
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
- National Center of Technology Innovation for Saline-Alkali Tolerant Rice in Sanya, Sanya, China
| | - Yijie Zhan
- Long Ping Branch, Graduate School of Hunan University, Changsha, China
| | - Junhao Dan
- Long Ping Branch, Graduate School of Hunan University, Changsha, China
| | - Ning Tang
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
| | - Junyou Tian
- Long Ping Branch, Graduate School of Hunan University, Changsha, China
| | - Mengliang Cao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
- National Center of Technology Innovation for Saline-Alkali Tolerant Rice in Sanya, Sanya, China
- Long Ping Branch, Graduate School of Hunan University, Changsha, China
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28
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Noyes RD. Mendelian segregation for parthenogenetic embryo development at the diploid level in the flowering plant Erigeron. Am J Bot 2022; 109:1641-1651. [PMID: 36112611 DOI: 10.1002/ajb2.16071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Parthenogenesis is the capacity of organisms to develop embryos from unfertilized eggs. When parthenogenesis is coupled with unreduced gamete formation (apomeiosis), genetically maternal progeny result. Genetic elucidation of this form of reproduction in plants, apomixis, has important agronomic implications. However, genetic characterization of apomeiosis and parthenogenesis has been problematic in part because the traits usually co-occur and are restricted to polyploids. In this work, the inheritance of parthenogenetic embryo development, by itself, was studied at the diploid level. METHODS Progeny resulting from a cross between a diploid (2n = 18), heterozygous, parthenogenetic pollen donor, and a diploid, wildtype, sexual seed parent were evaluated. Paternity was tested with conserved orthologous sequence (COS) markers, reproductive development of F1s was evaluated with microscopy of cleared ovules, and an amplified fragment length polymorphism (AFLP) marker (Eagc × Macg.615) co-segregating with parthenogenesis was characterized at the sequence level. RESULTS Of 102 diploid biparental progeny, 47 exhibited parthenogenetic embryo and endosperm development, and 55 lacked development of the egg and central cell. This result is consistent with Mendelian inheritance for a single locus (P = 0.43). Isolation and sequencing of the AFLP marker indicates that it is likely a portion of a Ty-Gypsy retrotransposon. Attempts to develop a sequence-characterized amplified region marker from the AFLP were unsuccessful. CONCLUSIONS This work shows that parthenogenesis can be transmitted simply at the diploid level. This advance is key in the development of a tractable system in Erigeron aimed at the identification of the parthenogenesis locus using genetic mapping strategies.
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Affiliation(s)
- Richard D Noyes
- Department of Biology, University of Central Arkansas, Conway, AR, US 72035
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29
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Wang N, Song X, Ye J, Zhang S, Cao Z, Zhu C, Hu J, Zhou Y, Huang Y, Cao S, Liu Z, Wu X, Chai L, Guo W, Xu Q, Gaut BS, Koltunow AMG, Zhou Y, Deng X. Structural variation and parallel evolution of apomixis in citrus during domestication and diversification. Natl Sci Rev 2022; 9:nwac114. [PMID: 36415319 PMCID: PMC9671666 DOI: 10.1093/nsr/nwac114] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 09/02/2023] Open
Abstract
Apomixis, or asexual seed formation, is prevalent in Citrinae via a mechanism termed nucellar or adventitious embryony. Here, multiple embryos of a maternal genotype form directly from nucellar cells in the ovule and can outcompete the developing zygotic embryo as they utilize the sexually derived endosperm for growth. Whilst nucellar embryony enables the propagation of clonal plants of maternal genetic constitution, it is also a barrier to effective breeding through hybridization. To address the genetics and evolution of apomixis in Citrinae, a chromosome-level genome of the Hongkong kumquat (Fortunella hindsii) was assembled following a genome-wide variation map including structural variants (SVs) based on 234 Citrinae accessions. This map revealed that hybrid citrus cultivars shelter genome-wide deleterious mutations and SVs into heterozygous states free from recessive selection, which may explain the capability of nucellar embryony in most cultivars during Citrinae diversification. Analyses revealed that parallel evolution may explain the repeated origin of apomixis in different genera of Citrinae. Within Fortunella, we found that apomixis of some varieties originated via introgression. In apomictic Fortunella, the locus associated with apomixis contains the FhRWP gene, encoding an RWP-RK domain-containing protein previously shown to be required for nucellar embryogenesis in Citrus. We found the heterozygous SV in the FhRWP and CitRWP promoters from apomictic Citrus and Fortunella, due to either two or three miniature inverted transposon element (MITE) insertions. A transcription factor, FhARID, encoding an AT-rich interaction domain-containing protein binds to the MITEs in the promoter of apomictic varieties, which facilitates induction of nucellar embryogenesis. This study provides evolutionary genomic and molecular insights into apomixis in Citrinae and has potential ramifications for citrus breeding.
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Affiliation(s)
- Nan Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Xietian Song
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Junli Ye
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Siqi Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Zhen Cao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Chenqiao Zhu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Jianbing Hu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yin Zhou
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yue Huang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Shuo Cao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| | - Zhongjie Liu
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| | - Xiaomeng Wu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Lijun Chai
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Wenwu Guo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Brandon S Gaut
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, USA
| | - Anna M G Koltunow
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane 4072, Australia
| | - Yongfeng Zhou
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
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Pasten MC, Carballo J, Gallardo J, Zappacosta D, Selva JP, Rodrigo JM, Echenique V, Garbus I. A combined transcriptome - miRNAome approach revealed that a kinesin gene is differentially targeted by a novel miRNA in an apomictic genotype of Eragrostis curvula. Front Plant Sci 2022; 13:1012682. [PMID: 36247597 PMCID: PMC9563718 DOI: 10.3389/fpls.2022.1012682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/14/2022] [Indexed: 06/06/2023]
Abstract
Weeping lovegrass (Eragrostis curvula [Shrad.] Nees) is a perennial grass typically established in semi-arid regions, with good adaptability to dry conditions and sandy soils. This polymorphic complex includes both sexual and apomictic cytotypes, with different ploidy levels (2x-8x). Diploids are known to be sexual, while most polyploids are facultative apomicts, and full apomicts have also been reported. Plant breeding studies throughout the years have focused on achieving the introgression of apomixis into species of agricultural relevance, but, given the complexity of the trait, a deeper understanding of the molecular basis of regulatory mechanisms of apomixis is still required. Apomixis is thought to be associated with silencing or disruption of the sexual pathway, and studies have shown it is influenced by epigenetic mechanisms. In a previous study, we explored the role of miRNA-mRNA interactions using two contrasting E. curvula phenotypes. Here, the sexual OTA-S, the facultative Don Walter and the obligate apomictic Tanganyika cDNA and sRNA libraries were inquired, searching for miRNA discovery and miRNA expression regulation of genes related to the reproductive mode. This allowed for the characterization of seven miRNAs and the validation of their miRNA-target interactions. Interestingly, a kinesin gene was found to be repressed in the apomictic cultivar Tanganyika, targeted by a novel miRNA that was found to be overexpressed in this genotype, suggestive of an involvement in the reproductive mode expression. Our work provided additional evidence of the contribution of the epigenetic regulation of the apomictic pathway.
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Affiliation(s)
- María Cielo Pasten
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - José Carballo
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Jimena Gallardo
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Diego Zappacosta
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Juan Pablo Selva
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Juan Manuel Rodrigo
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Viviana Echenique
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Ingrid Garbus
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
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Karbstein K, Tomasello S, Hodač L, Wagner N, Marinček P, Barke BH, Paetzold C, Hörandl E. Untying Gordian knots: unraveling reticulate polyploid plant evolution by genomic data using the large Ranunculus auricomus species complex. New Phytol 2022; 235:2081-2098. [PMID: 35633497 DOI: 10.1111/nph.18284] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
Speciation via hybridization and polyploidization is a major evolutionary force in plant evolution but is still poorly understood for neopolyploid groups. Challenges are attributed to high heterozygosity, low genetic divergence, and missing information on progenitors, ploidy, and reproduction. We study the large Eurasian Ranunculus auricomus species complex and use a comprehensive workflow integrating reduced-representation sequencing (RRS) genomic data to unravel reticulate evolution, genome diversity and composition of polyploids. We rely on 97 312 restriction site-associated DNA sequencing (RAD-Seq) loci, 576 targeted nuclear genes (48 phased), and 71 plastid regions derived from 78 polyploid apomictic taxa and four diploid and one tetraploid putative sexual progenitor species. We applied (phylo)genomic structure, network, and single nucleotide polymorphism (SNP)-origin analyses. Results consistently showed only 3-5 supported and geographically structured polyploid genetic groups, each containing extant sexual and one unknown progenitor species. Combined analyses demonstrated predominantly allopolyploid origins, each involving 2-3 different diploid sexual progenitor species. Young allotetraploids were characterized by subgenome dominance and nonhybrid SNPs, suggesting substantial post-origin but little lineage-specific evolution. The biodiversity of neopolyploid complexes can result from multiple hybrid origins involving different progenitors and substantial post-origin evolution (e.g. homoeologous exchanges, hybrid segregation, gene flow). Reduced-representation sequencing genomic data including multi-approach information is efficient to delimit shallow reticulate relationships.
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Affiliation(s)
- Kevin Karbstein
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
- Georg-August University School of Science (GAUSS), University of Göttingen, 37073, Göttingen, Germany
| | - Salvatore Tomasello
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Ladislav Hodač
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, 07745, Jena, Germany
| | - Natascha Wagner
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Pia Marinček
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Birthe Hilkka Barke
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Claudia Paetzold
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
- Department of Botany and Molecular Evolution, Senckenberg Research Institute, 60325, Frankfurt (Main), Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
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Chahal LS, Conner JA, Ozias-Akins P. Phylogenetically Distant BABY BOOM Genes From Setaria italica Induce Parthenogenesis in Rice. Front Plant Sci 2022; 13:863908. [PMID: 35909735 PMCID: PMC9329937 DOI: 10.3389/fpls.2022.863908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 06/13/2022] [Indexed: 06/02/2023]
Abstract
The combination of apomixis and hybrid production is hailed as the holy grail of agriculture for the ability of apomixis to fix heterosis of F1 hybrids in succeeding generations, thereby eliminating the need for repeated crosses to produce F1 hybrids. Apomixis, asexual reproduction through seed, achieves this feat by circumventing two processes that are fundamental to sexual reproduction (meiosis and fertilization) and replacing them with apomeiosis and parthenogenesis, resulting in seeds that are clonal to the maternal parent. Parthenogenesis, embryo development without fertilization, has been genetically engineered in rice, maize, and pearl millet using PsASGR-BABY BOOM-like (PsASGR-BBML) transgenes and in rice using the OsBABY BOOM1 (OsBBM1) cDNA sequence when expressed under the control of egg cell-specific promoters. A phylogenetic analysis revealed that BABY BOOM (BBM)/BBML genes from monocots cluster within three different clades. The BBM/BBML genes shown to induce parthenogenesis cluster within clade 1 (the ASGR-BBML clade) along with orthologs from other monocot species, such as Setaria italica. For this study, we tested the parthenogenetic potential of three BBM transgenes from S. italica, each a member of a different phylogenetic BBM clade. All transgenes were genomic constructs under the control of the AtDD45 egg cell-specific promoter. All SiBBM transgenes induced various levels of parthenogenetic embryo development, resulting in viable haploid T1 seedlings. Poor seed set and lower haploid seed production were characteristics of multiple transgenic lines. The results presented in this study illustrate that further functional characterization of BBMs in zygote/embryo development is warranted.
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Affiliation(s)
- Lovepreet Singh Chahal
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Tifton, GA, United States
| | - Joann A. Conner
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Tifton, GA, United States
- Department of Horticulture, University of Georgia, Tifton, GA, United States
| | - Peggy Ozias-Akins
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Tifton, GA, United States
- Department of Horticulture, University of Georgia, Tifton, GA, United States
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Mau M, Mandáková TM, Ma X, Ebersbach J, Zou L, Lysak MA, Sharbel TF. Evolution of an Apomixis-Specific Allele Class in Supernumerary Chromatin of Apomictic Boechera. Front Plant Sci 2022; 13:890038. [PMID: 35720540 PMCID: PMC9198585 DOI: 10.3389/fpls.2022.890038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/03/2022] [Indexed: 06/06/2023]
Abstract
Asexual reproduction through seeds in plants (i.e., apomixis) is a heritable trait, and apomixis- linked loci have been identified in multiple species. However, direct identification of genomic elements is typically hindered as apomixis-linked loci and are commonly found in recombination-suppressed and repetitive regions. Heterochromatinized elements, such as B chromosomes and other supernumerary chromosomal DNA fragments have long been known to be associated with asexuality in both plants and animals and are prime candidate regions for the evolution of multiple apomixis factors controlling the individual elements of apomixis. Here, we examined molecular evolution, gene regulation, and chromosomal location of a male apomeiosis factor (UPG2), a long noncoding RNA gene, in sexual and apomictic Boechera with and without male apomeiosis (i.e., balanced and unbalanced apomicts). We revealed the origin of the gene in the apomixis genome on an apomixis-specific, supernumerary heterochromatic Boechera chromosome (Boe1). The UPG2 is active in the tapetum at male meiosis. We found allele classes specific to apomictic and sexual Boechera accessions and a third class that shares the features of both and points to a convergent transition state. Sex alleles are found only in some of the sexual accessions and have higher nucleotide divergence and lower transcriptional activity compared to apo alleles. These data demonstrate selective pressure to maintain the function of UPG2 for unreduced pollen formation in apomicts as the occasional transmission of the allele from unbalanced apomicts into sexual organisms that lead to pseudogenization and functional decay of copies in sexual organisms.
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Affiliation(s)
- Martin Mau
- Apomixis Research Group, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Xingliang Ma
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jana Ebersbach
- Saskatoon Research and Development Centre, Saskatoon, SK, Canada
| | - Lifang Zou
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Martin A. Lysak
- Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Timothy F. Sharbel
- Apomixis Research Group, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
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Abstract
Apomixis is a form of reproduction leading to clonal seeds and offspring that are genetically identical to the maternal plant. While apomixis naturally occurs in hundreds of plant species distributed across diverse plant families, it is absent in major crop species. Apomixis has a revolutionary potential in plant breeding, as it could allow the instant fixation and propagation though seeds of any plant genotype, most notably F1 hybrids. Mastering and implementing apomixis would reduce the cost of hybrid seed production, facilitate new types of hybrid breeding, and make it possible to harness hybrid vigor in crops that are not presently cultivated as hybrids. Synthetic apomixis can be engineered by combining modifications of meiosis and fertilization. Here, we review the current knowledge and recent major achievements toward the development of efficient apomictic systems usable in agriculture.
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Affiliation(s)
- Charles J Underwood
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany; ,
| | - Raphael Mercier
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany; ,
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Nitta JH, Mishler BD, Iwasaki W, Ebihara A. Spatial phylogenetics of Japanese ferns: Patterns, processes, and implications for conservation. Am J Bot 2022; 109:727-745. [PMID: 35435239 PMCID: PMC9325522 DOI: 10.1002/ajb2.1848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/11/2022] [Accepted: 03/11/2022] [Indexed: 06/02/2023]
Abstract
PREMISE Biodiversity is often only measured with species richness; however, this metric ignores evolutionary history and is not sufficient for making conservation decisions. Here, we characterize multiple facets and drivers of biodiversity to understand how these relate to bioregions and conservation status in the ferns of Japan. METHODS We compiled a community data set of 1239 grid cells (20 × 20 km each) including 672 taxa based on >300,000 specimen records. We combined the community data with a phylogeny and functional traits to analyze taxonomic, phylogenetic, and functional diversity and modeled biodiversity metrics in response to environmental factors and reproductive mode. Hierarchical clustering was used to delimit bioregions. Conservation status and threats were assessed by comparing the overlap of significantly diverse grid cells with conservation zones and range maps of native Japanese deer. RESULTS Taxonomic richness was highest at mid-latitudes. Phylogenetic and functional diversity and phylogenetic endemism were highest in small southern islands. Relative phylogenetic and functional diversity were high at high and low latitudes, and low at mid-latitudes. Grid cells were grouped into three (phylogenetic) or four (taxonomic) major bioregions. Temperature and apomixis were identified as drivers of biodiversity patterns. Conservation status was generally high for grid cells with significantly high biodiversity, but the threat due to herbivory by deer was greater for taxonomic richness than other metrics. CONCLUSIONS Our integrative approach reveals previously undetected patterns and drivers of biodiversity in the ferns of Japan. Future conservation efforts should recognize that threats can vary by biodiversity metric and consider multiple metrics when establishing conservation priorities.
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Affiliation(s)
- Joel H. Nitta
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
| | - Brent D. Mishler
- University and Jepson Herbaria, and Department of Integrative BiologyUniversity of CaliforniaBerkeleyCAUSA
| | - Wataru Iwasaki
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoTokyoJapan
- Department of Integrated Biosciences, Graduate School of Frontier SciencesThe University of TokyoChibaJapan
| | - Atsushi Ebihara
- Department of BotanyNational Museum of Nature and ScienceTsukubaJapan
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Proença CEB, Tuler AC, Lucas EJ, Vasconcelos TNDC, de Faria JEQ, Staggemeier VG, de-Carvalho PS, Forni-Martins ER, Inglis PW, da Mata LR, da Costa IR. Diversity, phylogeny and evolution of the rapidly evolving genus Psidium L. (Myrtaceae, Myrteae). Ann Bot 2022; 129:367-388. [PMID: 35034117 PMCID: PMC8944734 DOI: 10.1093/aob/mcac005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND AIMS Psidium is the fourthth largest genus of Myrtaceae in the Neotropics. Psidium guajava is widely cultivated in the tropics for its edible fruit. It is commercially under threat due to the disease guava decline. Psidium cattleyanum is one of the 100 most invasive organisms in the world. Knowledge of the phylogenetic relationships within Psidium is poor. We aim to provide a review of the biology, morphology and ecology of Psidium, a phylogenetic tree, an infrageneric classification and a list of species. METHODS Morphological and geographic data were obtained by studying Psidium in herbaria and in the field between 1988 and 2020. Forty-six herbaria were visited personally. A database of approx. 6000 specimens was constructed, and the literature was reviewed. Thirty species (about a third of the species in the genus) were sampled for molecular phylogenetic inference. Two chloroplast (psbA-trnH and ndhF) and two nuclear (external transcribed spacer and internal transcribed spacer) regions were targeted. Phylogenetic trees were constructed using maximum likelihood (ML; RaxML) and Bayesian inference (BI; MrBayes). KEY RESULTS Psidium is a monophyletic genus with four major clades recognized as sections. Section Psidium (ten species), to which P. guajava belongs, is sister to the rest of the genus; it is widespread across the Neotropics. Section Obversifolia (six species; restricted to the Brazilian Atlantic Forest), which includes P. cattleyanum, is sister to the innermost clade composed of sister sections Apertiflora (31 species; widespread but most diverse in the Brazilian Atlantic Forest) + Mitranthes (26 species; widespread in dry forests and probably diverse in the Caribbean). Characters associated with diversification within Psidium are discussed. CONCLUSIONS Research on pre-foliation, colleters, leaf anatomy, leaf physiology, staminal development, placentation and germination associated with the anatomy of the opercular plug is desirable. Studies are biased towards sections Psidium and Obversifolia, with other sections poorly known.
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Affiliation(s)
| | - Amélia Carlos Tuler
- Instituto Nacional da Mata Atlântica, Av. José Ruschi 4, Santa Teresa, ES, CEP, Brazil
| | | | | | | | - Vanessa Graziele Staggemeier
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, R. das Biociências, Lagoa Nova, Natal, RN, CEP, Brazil
| | | | | | | | - Lorena Ramos da Mata
- Empresa Brasileira de Pesquisa Agropecuária, Recursos Genéticos e Biotecnologia (EMBRAPA CENARGEN)
, SAIN Parque Rural, W5, Asa Norte, Brasília, DF, Brazil
| | - Itayguara Ribeiro da Costa
- Departamento de Biologia, Universidade Federal do Ceará, Campus do Pici Bloco 906, Fortaleza, CE, Brazil
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Yin PP, Tang LP, Zhang XS, Su YH. Options for Engineering Apomixis in Plants. Front Plant Sci 2022; 13:864987. [PMID: 35371148 PMCID: PMC8967160 DOI: 10.3389/fpls.2022.864987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
In plants, embryogenesis and reproduction are not strictly dependent on fertilization. Several species can produce embryos in seeds asexually, a process known as apomixis. Apomixis is defined as clonal asexual reproduction through seeds, whereby the progeny is identical to the maternal genotype, and provides valuable opportunities for developing superior cultivars, as its induction in agricultural crops can facilitate the development and maintenance of elite hybrid genotypes. In this review, we summarize the current understanding of apomixis and highlight the successful introduction of apomixis methods into sexual crops. In addition, we discuss several genes whose overexpression can induce somatic embryogenesis as candidate genes to induce parthenogenesis, a unique reproductive method of gametophytic apomixis. We also summarize three schemes to achieve engineered apomixis, which will offer more opportunities for the realization of apomictic reproduction.
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Hornych O, Černochová L, Lisner A, Ekrt L. An experimental assessment of competitive interactions between sexual and apomictic fern gametophytes using Easy Leaf Area. Appl Plant Sci 2022; 10:e11466. [PMID: 35495190 PMCID: PMC9039791 DOI: 10.1002/aps3.11466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 05/14/2023]
Abstract
PREMISE Few studies have explored competition in fern gametophyte populations. One limiting factor is the tedious measurement of gametophyte size as a proxy for biomass in these small plants. Here, an alternative approach of estimating the number of green pixels from photos was employed to measure the competitive interactions among apomictic and sexual Dryopteris gametophytes. METHODS We cultivated the gametophytes of two apomictic (diploid and triploid) and one sexual (tetraploid) Dryopteris species in monocultures and in two-species mixtures in the ratios 1 : 1 and 1 : 3. The total gametophyte cover of each population originating from 20 spores was assessed using Easy Leaf Area. Assessments were performed weekly between weeks 4 and 10 of cultivation. Additionally, during week 5, the cover of each species in each mixture was estimated separately. RESULTS We identified a positive correlation between gametophyte size and ploidy level as well as sexual reproduction. The performance of the tested species in mixtures was dependent on the competitor species identity, indicating the importance of competition between gametophytes. DISCUSSION The methods outlined can be used for a rapid assessment of fern gametophyte cover in large gametophyte populations. Ploidy level and reproduction type seem to play a major role in the competitive abilities of fern gametophytes, but more research is needed on this topic.
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Affiliation(s)
- Ondřej Hornych
- Department of Botany, Faculty of ScienceUniversity of South BohemiaBranišovská 1760, České Budějovice, CZ‐37005Czech Republic
| | - Lucie Černochová
- Department of Botany, Faculty of ScienceUniversity of South BohemiaBranišovská 1760, České Budějovice, CZ‐37005Czech Republic
| | - Aleš Lisner
- Department of Botany, Faculty of ScienceUniversity of South BohemiaBranišovská 1760, České Budějovice, CZ‐37005Czech Republic
| | - Libor Ekrt
- Department of Botany, Faculty of ScienceUniversity of South BohemiaBranišovská 1760, České Budějovice, CZ‐37005Czech Republic
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Hörandl E. Novel Approaches for Species Concepts and Delimitation in Polyploids and Hybrids. Plants (Basel) 2022; 11:plants11020204. [PMID: 35050093 PMCID: PMC8781807 DOI: 10.3390/plants11020204] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 05/08/2023]
Abstract
Hybridization and polyploidization are important processes for plant evolution. However, classification of hybrid or polyploid species has been notoriously difficult because of the complexity of processes and different evolutionary scenarios that do not fit with classical species concepts. Polyploid complexes are formed via combinations of allopolyploidy, autopolyploidy and homoploid hybridization with persisting sexual reproduction, resulting in many discrete lineages that have been classified as species. Polyploid complexes with facultative apomixis result in complicated net-work like clusters, or rarely in agamospecies. Various case studies illustrate the problems that apply to traditional species concepts to hybrids and polyploids. Conceptual progress can be made if lineage formation is accepted as an inevitable consequence of meiotic sex, which is established already in the first eukaryotes as a DNA restoration tool. The turnaround of the viewpoint that sex forms species as lineages helps to overcome traditional thinking of species as "units". Lineage formation and self-sustainability is the prerequisite for speciation and can also be applied to hybrids and polyploids. Species delimitation is aided by the improved recognition of lineages via various novel -omics methods, by understanding meiosis functions, and by recognizing functional phenotypes by considering morphological-physiological-ecological adaptations.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, 37073 Göttingen, Germany
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Fernández H, Grossmann J, Gagliardini V, Feito I, Rivera A, Rodríguez L, Quintanilla LG, Quesada V, Cañal MJ, Grossniklaus U. Sexual and Apogamous Species of Woodferns Show Different Protein and Phytohormone Profiles. Front Plant Sci 2021; 12:718932. [PMID: 34868105 PMCID: PMC8633544 DOI: 10.3389/fpls.2021.718932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
The gametophyte of ferns reproduces either by sexual or asexual means. In the latter, apogamy represents a peculiar case of apomixis, in which an embryo is formed from somatic cells. A proteomic and physiological approach was applied to the apogamous fern Dryopteris affinis ssp. affinis and its sexual relative D. oreades. The proteomic analysis compared apogamous vs. female gametophytes, whereas the phytohormone study included, in addition to females, three apogamous stages (filamentous, spatulate, and cordate). The proteomic profiles revealed a total of 879 proteins and, after annotation, different regulation was found in 206 proteins of D. affinis and 166 of its sexual counterpart. The proteins upregulated in D. affinis are mostly associated to protein metabolism (including folding, transport, and proteolysis), ribosome biogenesis, gene expression and translation, while in the sexual counterpart, they account largely for starch and sucrose metabolism, generation of energy and photosynthesis. Likewise, ultra-performance liquid chromatography-tandem spectrometry (UHPLC-MS/MS) was used to assess the levels of indol-3-acetic acid (IAA); the cytokinins: 6-benzylaminopurine (BA), trans-Zeatine (Z), trans-Zeatin riboside (ZR), dyhidrozeatine (DHZ), dyhidrozeatin riboside (DHZR), isopentenyl adenine (iP), isopentenyl adenosine (iPR), abscisic acid (ABA), the gibberellins GA3 and GA4, salicylic acid (SA), and the brassinosteroids: brassinolide (BL) and castasterone (CS). IAA, the cytokinins Z, ZR, iPR, the gibberellin GA4, the brassinosteoids castasterone, and ABA accumulated more in the sexual gametophyte than in the apogamous one. When comparing the three apogamous stages, BA and SA peaked in filamentous, GA3 and BL in spatulate and DHRZ in cordate gametophytes. The results point to the existence of large metabolic differences between apogamous and sexual gametophytes, and invite to consider the fern gametophyte as a good experimental system to deepen our understanding of plant reproduction.
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Affiliation(s)
- Helena Fernández
- Area of Plant Physiology, Department of Organisms and Systems Biology, Oviedo University, Oviedo, Spain
| | - Jonas Grossmann
- Functional Genomics Center, Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Valeria Gagliardini
- Department of Plant and Microbial Biology & Zurich and Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Isabel Feito
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Finca Experimental La Mata, Grado, Spain
| | - Alejandro Rivera
- Area of Plant Physiology, Department of Organisms and Systems Biology, Oviedo University, Oviedo, Spain
| | - Lucía Rodríguez
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Finca Experimental La Mata, Grado, Spain
| | - Luis G. Quintanilla
- Department of Biology and Geology, Physics and Inorganic Chemistry, Rey Juan Carlos University, Móstoles, Spain
| | - Víctor Quesada
- Department of Biochemistry and Molecular Biology, Institute of Oncology of the Principality of Asturias, Oviedo University, Móstoles, Spain
| | - Mª Jesús Cañal
- Area of Plant Physiology, Department of Organisms and Systems Biology, Oviedo University, Oviedo, Spain
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich and Basel Plant Science Center, University of Zurich, Zurich, Switzerland
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Picard KT, Ranft H, Grusz AL, Windham MD, Schuettpelz E. When it only takes one to tango: assessing the impact of apomixis in the fern genus Pteris. Am J Bot 2021; 108:2220-2234. [PMID: 34618360 PMCID: PMC9298017 DOI: 10.1002/ajb2.1761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 07/30/2021] [Accepted: 08/12/2021] [Indexed: 05/14/2023]
Abstract
PREMISE Apomixis (asexual reproduction by seed, spore, or egg) has evolved repeatedly across the tree of life. Studies of animals and angiosperms show that apomictic lineages are often evolutionarily short-lived and frequently exhibit different distributions than their sexual relatives. However, apomixis is rare in these groups. Less is known about the role of apomixis in the evolution and biogeography of ferns, in which ~10% of species are apomictic. Apomixis is especially common in the fern genus Pteris (34-39% of species); however, because of the limited taxonomic and geographic sampling of previous studies, the true frequency of apomixis and its associations with geography and phylogeny in this lineage remain unclear. METHODS We used spore analyses of herbarium specimens to determine reproductive mode for 127 previously unsampled Pteris species. Then we leveraged biogeographic and phylogenetic analyses to estimate the global distribution and evolution of apomixis in Pteris. RESULTS Among all Pteris species examined, we found that 21% are exclusively apomictic, 71% are exclusively sexual, and 8% have conflicting reports. Apomixis is unevenly distributed across the range of the genus, with the Paleotropics exhibiting the highest frequency, and has evolved numerous times across the Pteris phylogeny, with predominantly East Asian and South Asian clades containing the most apomictic species. CONCLUSIONS Apomixis arises frequently in Pteris, but apomictic species do not appear to diversify. Species that encompass both apomictic and sexual populations have wider ranges than exclusively sexual or apomictic species, which suggests that sexual and apomictic ferns could occupy separate ecological niches.
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Affiliation(s)
- Kathryn T. Picard
- Department of Botany, National Museum of Natural HistorySmithsonian InstitutionWashingtonDC20560USA
| | - Hannah Ranft
- Department of Botany, National Museum of Natural HistorySmithsonian InstitutionWashingtonDC20560USA
- Johns Hopkins UniversityBaltimoreMaryland21218USA
- Department of BiologyUniversity of Minnesota DuluthDuluthMinnesota55812USA
| | - Amanda L. Grusz
- Department of BiologyUniversity of Minnesota DuluthDuluthMinnesota55812USA
| | | | - Eric Schuettpelz
- Department of Botany, National Museum of Natural HistorySmithsonian InstitutionWashingtonDC20560USA
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Kuo L, Tang SK, Kao T, Ebihara A, Fawcett S, Hsiao M, Shinohara W, Dauphin B. A dormant resource for genome size estimation in ferns: C-value inference of the Ophioglossaceae using herbarium specimen spores. Appl Plant Sci 2021; 9:e11452. [PMID: 34938613 PMCID: PMC8664048 DOI: 10.1002/aps3.11452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 06/14/2023]
Abstract
PREMISE The great variation of genome size (C-value) across land plants is linked to various adaptative features. Flow cytometry (FCM), the standard approach to estimating C-values, relies mostly on fresh materials, performing poorly when used with herbarium materials. No fern C-value reports have been derived from herbarium specimens; however, the herbarium spores of some ferns remain highly viable for decades and are thus promising for further investigation. To explore this possibility, we evaluated herbarium spore collections of Ophioglossaceae ferns using FCM. METHODS Flow cytometry was conducted on 24 spore samples, representing eight of the 12 genera of the Ophioglossaceae, using specimens ranging in age from 2.6 to 111 years obtained from five herbaria. RESULTS Regardless of the genus or the source herbarium, high-quality C-value data were generated from 17 samples, with the oldest being 26 years old. Estimates of the C-values from sporophytic tissues of known ploidy did not reveal any evidence of apomixis for the species surveyed here. We also detected a pronounced genome downsizing in Sceptridium polyploids. DISCUSSION The recent success of FCM for C-value estimation using spores provides a much more convenient method of utilizing "dry" refrigerated materials. We demonstrate here that herbarium spores of some ferns are also promising for this use, even for older specimens.
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Affiliation(s)
- Li‐Yaung Kuo
- Institute of Molecular and Cellular BiologyNational Tsing Hua UniversityHsinchu CityTaiwan
| | - Sheng Kai Tang
- Institute of Molecular and Cellular BiologyNational Tsing Hua UniversityHsinchu CityTaiwan
| | - Tzu‐Tong Kao
- Department of BiologyDuke UniversityDurhamNorth CarolinaUSA
- Institute of Plant and Microbial BiologyAcademia SinicaTaipei CityTaiwan
| | - Atsushi Ebihara
- Department of BotanyNational Museum of Nature and Science, TsukubaIbarakiJapan
| | - Susan Fawcett
- University and Jepson Herbaria, University of California, BerkeleyCaliforniaUSA
| | - Min‐Chien Hsiao
- Institute of Ecology and Evolutionary BiologyNational Taiwan UniversityTaipei CityTaiwan
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Karunarathne P, Hojsgaard D. Single Independent Autopolyploidization Events From Distinct Diploid Gene Pools and Residual Sexuality Support Range Expansion of Locally Adapted Tetraploid Genotypes in a South American Grass. Front Genet 2021; 12:736088. [PMID: 34671384 PMCID: PMC8520906 DOI: 10.3389/fgene.2021.736088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 09/07/2021] [Indexed: 12/02/2022] Open
Abstract
Polyploidy plays a major role in plant evolution. The establishment of new polyploids is often a consequence of a single or few successful polyploidization events occurring within a species’ evolutionary trajectory. New polyploid lineages can play different roles in plant diversification and go through several evolutionary stages influenced by biotic and abiotic constraints and characterized by extensive genetic changes. The study of such changes has been crucial for understanding polyploid evolution. Here, we use the multiploid-species Paspalum intermedium to study population-level genetic and morphological variation and ecological differentiation in polyploids. Using flow cytometry, amplified fragment length polymorphism (AFLP) genetic markers, environmental variables, and morphological data, we assessed variations in ploidy, reproductive modes, and the genetic composition in 35 natural populations of P. intermedium along a latitudinal gradient in South America. Our analyses show that apomictic auto-tetraploids are of multiple independent origin. While overall genetic variation was higher in diploids, both diploids and tetraploids showed significant variation within and among populations. The spatial distribution of genetic variation provides evidence for a primary origin of the contact zone between diploids and tetraploids and further supports the hypothesis of geographic displacement between cytotypes. In addition, a strong link between the ecological differentiation of cytotypes and spatial distribution of genetic variation was observed. Overall, the results indicate that polyploidization in P. intermedium is a recurrent phenomenon associated to a shift in reproductive mode and that multiple polyploid lineages from genetically divergent diploids contributed to the successful establishment of local polyploid populations and dispersal into new environments.
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Affiliation(s)
- Piyal Karunarathne
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany.,Georg-August University School of Science, University of Goettingen, Goettingen, Germany.,Evolutionary Biology Center, Uppsala University, Uppsala, Sweden
| | - Diego Hojsgaard
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany.,Taxonomy & Evolutionary Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
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Jia HH, Xu YT, Yin ZP, Wu XM, Qing M, Fan YJ, Song X, Xie KD, Xie ZZ, Xu Q, Deng XX, Guo WW. Transcriptomes and DNA methylomes in apomictic cells delineate nucellar embryogenesis initiation in citrus. DNA Res 2021; 28:6356518. [PMID: 34424285 PMCID: PMC8476932 DOI: 10.1093/dnares/dsab014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/20/2021] [Indexed: 12/13/2022] Open
Abstract
Citrus nucellar poly-embryony (NPE) is a mode of sporophytic apomixis that asexual embryos formed in the seed through adventitious embryogenesis from the somatic nucellar cells. NPE allows clonal propagation of rootstocks, but it impedes citrus cross breeding. To understand the cellular processes involved in NPE initiation, we profiled the transcriptomes and DNA methylomes in laser microdissection captured citrus apomictic cells. In apomictic cells, ribosome biogenesis and protein degradation were activated, whereas auxin polar transport was repressed. Reactive oxygen species (ROS) accumulated in the poly-embryonic ovules, and response to oxidative stress was provoked. The global DNA methylation level, especially that of CHH context, was decreased, whereas the methylation level of the NPE-controlling key gene CitRWP was increased. A C2H2 domain-containing transcription factor gene and CitRWP co-expressed specifically in apomictic cells may coordinate to initiate NPE. The activated embryogenic development and callose deposition processes indicated embryogenic fate of nucellar embryo initial (NEI) cells. In our working model for citrus NPE initiation, DNA hyper-methylation may activate transcription of CitRWP, which increases C2H2 expression and ROS accumulation, triggers epigenetic regulation and regulates cell fate transition and NEI cell identity in the apomictic cells.
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Affiliation(s)
- Hui-Hui Jia
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuan-Tao Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhao-Ping Yin
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiao-Meng Wu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Mei Qing
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yan-Jie Fan
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xin Song
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Kai-Dong Xie
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zong-Zhou Xie
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiu-Xin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wen-Wu Guo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
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Ulum FB, Hadacek F, Hörandl E. Polyploidy Improves Photosynthesis Regulation within the Ranunculus auricomus Complex (Ranunculaceae). Biology (Basel) 2021; 10:biology10080811. [PMID: 34440043 PMCID: PMC8389576 DOI: 10.3390/biology10080811] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 01/10/2023]
Abstract
Simple Summary Genome duplication or multiplication, polyploidy, has contributed substantially to the evolutionary success of plants. Polyploidy is often connected to a higher resilience to environmental stress. We have chosen the goldilocks, the Ranunculus auricomus complex, to study effects of light stress. In this species complex, diploid (2x), tetraploid (4x), and hexaploid (6x) cytotypes occur in Central Europe in both shaded and sun-exposed habitats. In this study, we exposed them to different photoperiods in climate growth chambers to explore how the efficiency of photosynthesis varied between the various ploidies (2x, 4x, and 6x). We used fluorescence experiments exploring the proportion of light that is captured for photosynthesis and the resulting energy fluxes. In addition, quenching coefficients can be calculated that inform about the capability of a plant to deal with excess light. We found that the polyploids can quench excess light better, which concurs with their adaptation to open habitats and their predominantly asexual mode of reproduction that is probably favored by low stress levels in the reproductive tissues. Abstract Polyploidy has substantially contributed to successful plant evolution, and is often connected to a higher resilience to environmental stress. We test the hypothesis that polyploids tolerate light stress better than diploids. The Ranunculus auricomus complex comprises diploid (2x), tetraploid (4x), and hexaploid (6x) cytotypes, the former of which occur in shaded habitats and the latter more in open, sun-exposed habitats in Central Europe. In this study, we experimentally explored the effects of ploidy and photoperiod extension on the efficiency of photosystem II in the three cytotypes in climate growth chambers. Quantum yields and various coefficients that can be calculated from light curve, Kautsky curve, and fluorescent transient OJIP experiments provided support for the hypothesis that, in comparison to diploids, the improved regulation of excess light by more efficient photochemical and non-chemical quenching in polyploids might have facilitated the adaptation to unshaded habitats. We suggest how lower stress levels in reproductive tissues of polyploids might have favored asexual reproduction.
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Affiliation(s)
- Fuad Bahrul Ulum
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073 Göttingen, Germany;
- Georg-August University School of Science (GAUSS), University of Göttingen, 37073 Göttingen, Germany
- Biology Department, Faculty of Mathematics and Sciences, Jember University, Jember 68121, Indonesia
| | - Franz Hadacek
- Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany;
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, 37073 Göttingen, Germany;
- Correspondence: ; Tel.: +49-551-39-7843
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Mráz P, Mrázová V. Greater reproductive assurance of asexual plant compared with sexual relative in a low-density sympatric population: Experimental evidence for pollen limitation. J Evol Biol 2021; 34:1503-1509. [PMID: 34331325 DOI: 10.1111/jeb.13910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 05/07/2021] [Accepted: 07/20/2021] [Indexed: 11/30/2022]
Abstract
High reproductive assurance is regarded as a key advantage of uniparentally reproducing organisms for establishing a new population. This demographic benefit should especially be relevant for plants with autonomous apomixis, that is those which produce seeds completely independently from mates and pollinators. Indeed, many autonomous apomicts occupy larger distributional ranges when compared to their sexual relatives, showing geographical parthenogenesis patterns. However, uniparental reproduction advantage has only rarely been quantified in natural populations and results provided a mixed support, partly because allopatric sexual and asexual populations were exposed to different environmental and pollination conditions causing considerable between-population variation in the level of reproductive assurance. Here, we compared the level and stability of reproductive assurance between sexual self-incompatible and asexual autonomously apomictic plants of Hieracium alpinum (Asteraceae) cultivated in a sympatric low-density population with two levels of spatial clumping of sexual plants. Overall, we found that the realized seed set (i.e. proportion of well-developed seeds per capitulum) of asexuals was ca. 3 times greater than that of sexuals (83% vs. 27%), whereas the variance of this trait expressed as coefficient of variation was ca. 4 times smaller in asexuals compared with sexuals (19% vs. 83%). Solitary sexual plants had more than 2 times lower realized seed set when compared to clumps composed of two spatially close (20-30 cm) sexual plants (13% vs. 34%). Our study provides experimental evidence for benefit of uniparental reproduction of asexuals in a sympatric situation when the availability of mates is limited. This, together with unpredictability of pollinator environment could provide autonomous apomicts with an ultimate demographic superiority during colonization reflected in geographical parthenogenesis observed in this species.
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Affiliation(s)
- Patrik Mráz
- Herbarium Collections and Department of Botany, Charles University, Praha, Czechia
| | - Viera Mrázová
- Herbarium Collections and Department of Botany, Charles University, Praha, Czechia
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Fei X, Shi Q, Lei Y, Wang S, Qi Y, Hu H, Wei A. Pollination promotes ABA synthesis but not sexual reproduction in the apomictic species Zanthoxylum bungeanum Maxim. Tree Physiol 2021; 41:1497-1509. [PMID: 33440426 DOI: 10.1093/treephys/tpab004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/20/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Apomixis is a form of reproduction that does not involve the fertilization of female gametes by male gametes but instead involves the production of offspring directly from the female parent. The offspring of apomixis are genetically identical to the female parent and inherit its traits. Therefore, apomixis has great potential for application to agricultural genetic breeding. However, it remains unclear whether apomictic species require pollination, and the impacts of pollination on such species are poorly understood. We investigated the effects of pollination on the apomictic species Zanthoxylum bungeanum Maxim. by analyzing its fertilization process, assembling its transcriptome, and measuring hormone concentrations, fruit setting rate and gene expression levels. Transcriptome sequencing of pollinated and unpollinated fruits resulted in a total of 69,131 PacBio reads. Of these, 7102 genes were up-regulated and 6491 genes were down-regulated. Analysis of the differentially expressed genes (DEGs) and construction of a weighted gene co-expression network showed that many DEGs were involved in plant hormone signal transduction, suggesting that hormonal signaling during development differs between pollinated and unpollinated fruit. The germination rate of Z. bungeanum pollen in vitro was only 11%, and pollen could not germinate in the embryo sac to complete fertilization. Although pollination did not enable Z. bungeanum to complete the sexual reproduction process, it significantly increased abscisic acid (ABA) concentration and fruit setting rate. Spraying 100 μg l-1 ABA also significantly increased the fruit setting rate. Therefore, ABA appears to be a key factor in the regulation of fruit setting in apomictic Z. bungeanum. Based on these results, we suggest that some male plants be cultivated in Z. bungeanum plantations or exogenous ABA be sprayed to increase the likelihood of pollination and thereby increase the fruit setting rate.
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Affiliation(s)
- Xitong Fei
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Qianqian Shi
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Yu Lei
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Shujie Wang
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Yichen Qi
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Haichao Hu
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
| | - Anzhi Wei
- College of Forestry, Northwest Agriculture and Forestry University, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
- Research Centre for Engineering and Technology of Zanthoxylum State Forestry Administration, No. 3 Taicheng Road, Yangling district, Xianyang City, Shaanxi Province, 712100, China
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Mazumder L, Kesseli R. Population structure, seasonal genotypic differentiation, and clonal diversity of weedy dandelions in three Boston area populations ( Taraxacum sp.). Ecol Evol 2021; 11:10926-10935. [PMID: 34429891 PMCID: PMC8366855 DOI: 10.1002/ece3.7870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/17/2021] [Accepted: 06/16/2021] [Indexed: 11/28/2022] Open
Abstract
Weedy dandelions have a worldwide distribution and thrive in urban environments despite a lack of sexual reproduction throughout most of its range. North American dandelions, introduced from Eurasia, are believed to be primarily, if not exclusively, apomictic triploids. In some European populations, apomicts co-occur with diploid sexual individuals and hybridizations can create genetically unique apomicts, which may subsequently disperse and establish new populations globally. Using six nuclear microsatellite markers and a cpDNA intergenic spacer, we investigate the impact of this unusual natural history on population structure and diversity in three urban Boston area dandelion populations. Our results show high levels of genetic diversity within populations, spatial population structure, and seasonal genotypic differentiation in flowering times. We find evidence that sexual reproduction and recombination, presumably in Europe, and extensive gene flow drive these patterns of diversity and create the appearance of panmixia despite the lack of evidence for local sexual reproduction.
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Affiliation(s)
- Lisa Mazumder
- Department of BiologyUniversity of Massachusetts BostonBostonMAUSA
| | - Rick Kesseli
- Department of BiologyUniversity of Massachusetts BostonBostonMAUSA
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Meirmans PG. Niche divergence contributes to geographical parthenogenesis in two dandelion taxa. J Evol Biol 2021; 34:1071-1086. [PMID: 33955626 PMCID: PMC8362108 DOI: 10.1111/jeb.13794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/29/2021] [Accepted: 04/25/2021] [Indexed: 12/11/2022]
Abstract
Many sexual-asexual complexes show a distinct pattern where the asexuals have larger and more northerly ranges than closely related sexuals. A prime candidate to explain this so-called "geographical parthenogenesis" is ecological niche divergence between the sexuals and asexuals. Modern niche modelling techniques allow testing niche divergence by directly comparing the niches of sexuals and asexuals. In this study, I use such techniques to perform range-wide tests of whether nine bioclimatic variables, including annual mean temperature and annual precipitation, contribute to geographical parthenogenesis in two dandelion taxa: Taraxacum section Ruderalia and Taraxacum section Erythrosperma, which are both comprised of sexual diploids and asexual triploids. For both sections, I found evidence of niche divergence, though the exact nature of this divergence was different for the two sections. In section Ruderalia, the sexuals preferred warmer and wetter conditions, whereas in section Erythrosperma, the sexuals preferred dryer conditions. Using Species Distribution Modelling, consistent differences between the sexuals and asexuals were found when looking at the niche determinants: the variables that are most important for modelling the distribution. Furthermore, and in contrast with theoretical expectations that predict that the sexuals should have a wider niche, in section Erythrosperma the asexuals were found to have a wider niche than the sexuals. In conclusion, differences in niche optima, niche determinants, and niche width all contribute to the pattern of geographical parthenogenesis of these two dandelion taxa. However, the results also indicate that the exact causation of geographical parthenogenesis is not uniform across taxa.
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Affiliation(s)
- Patrick G Meirmans
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
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Tomaszewska P, Pellny TK, Hernández LM, Mitchell RAC, Castiblanco V, de Vega JJ, Schwarzacher T, Heslop-Harrison P(J. Flow Cytometry-Based Determination of Ploidy from Dried Leaf Specimens in Genomically Complex Collections of the Tropical Forage Grass Urochloa s. l. Genes (Basel) 2021; 12:957. [PMID: 34201593 PMCID: PMC8306847 DOI: 10.3390/genes12070957] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/09/2021] [Accepted: 06/16/2021] [Indexed: 01/31/2023] Open
Abstract
Urochloa (including Brachiaria, Megathyrus and some Panicum) tropical grasses are native to Africa and are now, after selection and breeding, planted worldwide, particularly in South America, as important forages with huge potential for further sustainable improvement and conservation of grasslands. We aimed to develop an optimized approach to determine ploidy of germplasm collection of this tropical forage grass group using dried leaf material, including approaches to collect, dry and preserve plant samples for flow cytometry analysis. Our methods enable robust identification of ploidy levels (coefficient of variation of G0/G1 peaks, CV, typically <5%). Ploidy of some 348 forage grass accessions (ploidy range from 2x to 9x), from international genetic resource collections, showing variation in basic chromosome numbers and reproduction modes (apomixis and sexual), were determined using our defined standard protocol. Two major Urochloa agamic complexes are used in the current breeding programs at CIAT and EMBRAPA: the 'brizantha' and 'humidicola' agamic complexes are variable, with multiple ploidy levels. Some U. brizantha accessions have odd level of ploidy (5x), and the relative differences in fluorescence values of the peak positions between adjacent cytotypes is reduced, thus more precise examination of this species is required. Ploidy measurement of U. humidicola revealed aneuploidy.
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Affiliation(s)
- Paulina Tomaszewska
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester LE1 7RH, UK; (T.S.); (P.H.-H.)
| | - Till K. Pellny
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK; (T.K.P.); (R.A.C.M.)
| | - Luis M. Hernández
- International Center for Tropical Agriculture (CIAT), Cali 6713, Colombia; (L.M.H.); (V.C.)
| | | | - Valheria Castiblanco
- International Center for Tropical Agriculture (CIAT), Cali 6713, Colombia; (L.M.H.); (V.C.)
| | - José J. de Vega
- Earlham Institute, Norwich Research Park, Norwich NR4 7UZ, UK;
| | - Trude Schwarzacher
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester LE1 7RH, UK; (T.S.); (P.H.-H.)
| | - Pat (J.S.) Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester LE1 7RH, UK; (T.S.); (P.H.-H.)
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