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Zeng ZH, Zhong L, Sun HY, Wu ZK, Wang X, Wang H, Li DZ, Barrett SCH, Zhou W. Parallel evolution of morphological and genomic selfing syndromes accompany the breakdown of heterostyly. THE NEW PHYTOLOGIST 2024; 242:302-316. [PMID: 38214455 DOI: 10.1111/nph.19522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/18/2023] [Indexed: 01/13/2024]
Abstract
Evolutionary transitions from outcrossing to selfing in flowering plants have convergent morphological and genomic signatures and can involve parallel evolution within related lineages. Adaptive evolution of morphological traits is often assumed to evolve faster than nonadaptive features of the genomic selfing syndrome. We investigated phenotypic and genomic changes associated with transitions from distyly to homostyly in the Primula oreodoxa complex. We determined whether the transition to selfing occurred more than once and investigated stages in the evolution of morphological and genomic selfing syndromes using 22 floral traits and both nuclear and plastid genomic data from 25 populations. Two independent transitions were detected representing an earlier and a more recently derived selfing lineage. The older lineage exhibited classic features of the morphological and genomic selfing syndrome. Although features of both selfing syndromes were less developed in the younger selfing lineage, they exhibited parallel development with the older selfing lineage. This finding contrasts with the prediction that some genomic changes should lag behind adaptive changes to morphological traits. Our findings highlight the value of comparative studies on the timing and extent of transitions from outcrossing to selfing between related lineages for investigating the tempo of morphological and molecular evolution.
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Affiliation(s)
- Zhi-Hua Zeng
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Zhong
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hua-Ying Sun
- School of Chinese Materia Medica, Yunnan University of Chinese Medicine, Kunming, Yunnan, 650500, China
| | - Zhi-Kun Wu
- Department of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, 550002, China
| | - Xin Wang
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Wei Zhou
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- Lijiang Forest Biodiversity National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang, Yunnan, 674100, China
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Wessinger CA, Katzer AM, Hime PM, Rausher MD, Kelly JK, Hileman LC. A few essential genetic loci distinguish Penstemon species with flowers adapted to pollination by bees or hummingbirds. PLoS Biol 2023; 21:e3002294. [PMID: 37769035 PMCID: PMC10538765 DOI: 10.1371/journal.pbio.3002294] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 08/11/2023] [Indexed: 09/30/2023] Open
Abstract
In the formation of species, adaptation by natural selection generates distinct combinations of traits that function well together. The maintenance of adaptive trait combinations in the face of gene flow depends on the strength and nature of selection acting on the underlying genetic loci. Floral pollination syndromes exemplify the evolution of trait combinations adaptive for particular pollinators. The North American wildflower genus Penstemon displays remarkable floral syndrome convergence, with at least 20 separate lineages that have evolved from ancestral bee pollination syndrome (wide blue-purple flowers that present a landing platform for bees and small amounts of nectar) to hummingbird pollination syndrome (bright red narrowly tubular flowers offering copious nectar). Related taxa that differ in floral syndrome offer an attractive opportunity to examine the genomic basis of complex trait divergence. In this study, we characterized genomic divergence among 229 individuals from a Penstemon species complex that includes both bee and hummingbird floral syndromes. Field plants are easily classified into species based on phenotypic differences and hybrids displaying intermediate floral syndromes are rare. Despite unambiguous phenotypic differences, genome-wide differentiation between species is minimal. Hummingbird-adapted populations are more genetically similar to nearby bee-adapted populations than to geographically distant hummingbird-adapted populations, in terms of genome-wide dXY. However, a small number of genetic loci are strongly differentiated between species. These approximately 20 "species-diagnostic loci," which appear to have nearly fixed differences between pollination syndromes, are sprinkled throughout the genome in high recombination regions. Several map closely to previously established floral trait quantitative trait loci (QTLs). The striking difference between the diagnostic loci and the genome as whole suggests strong selection to maintain distinct combinations of traits, but with sufficient gene flow to homogenize the genomic background. A surprisingly small number of alleles confer phenotypic differences that form the basis of species identity in this species complex.
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Affiliation(s)
- Carolyn A. Wessinger
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
| | - Amanda M. Katzer
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Paul M. Hime
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, Kansas, United States of America
| | - Mark D. Rausher
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - John K. Kelly
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
| | - Lena C. Hileman
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
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Zhang Z, Kryvokhyzha D, Orsucci M, Glémin S, Milesi P, Lascoux M. How broad is the selfing syndrome? Insights from convergent evolution of gene expression across species and tissues in the Capsella genus. THE NEW PHYTOLOGIST 2022; 236:2344-2357. [PMID: 36089898 PMCID: PMC9828073 DOI: 10.1111/nph.18477] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
The shift from outcrossing to selfing is one of the main evolutionary transitions in plants. It is accompanied by profound effects on reproductive traits, the so-called selfing syndrome. Because the transition to selfing also implies deep genomic and ecological changes, one also expects to observe a genomic selfing syndrome. We took advantage of the three independent transitions from outcrossing to selfing in the Capsella genus to characterize the overall impact of mating system change on RNA expression, in flowers but also in leaves and roots. We quantified the extent of both selfing and genomic syndromes, and tested whether changes in expression corresponded to adaptation to selfing or to relaxed selection on traits that were constrained in outcrossers. Mating system change affected gene expression in all three tissues but more so in flowers than in roots and leaves. Gene expression in selfing species tended to converge in flowers but diverged in the two other tissues. Hence, convergent adaptation to selfing dominates in flowers, whereas genetic drift plays a more important role in leaves and roots. The effect of mating system transition is not limited to reproductive tissues and corresponds to both adaptation to selfing and relaxed selection on previously constrained traits.
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Affiliation(s)
- Zebin Zhang
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
| | - Dmytro Kryvokhyzha
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
- Department of Clinical SciencesLund University Diabetes Centre214 28MalmöSweden
| | - Marion Orsucci
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
- Department of Plant BiologySwedish University of Agricultural Sciences, Uppsala BioCenter750 07UppsalaSweden
| | - Sylvain Glémin
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
- Université de Rennes, Centre National de la Recherche Scientifique (CNRS), ECOBIO (Ecosystèmes, Biodiversité, Evolution) – Unité Mixte de Recherche (UMR) 6553F‐35042RennesFrance
| | - Pascal Milesi
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
- Science For Life Laboratory (SciLifeLab)752 37UppsalaSweden
| | - Martin Lascoux
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology CentreUppsala UniversityNorbyvägen 18D752 36UppsalaSweden
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Huang X, Chen M, Wang L, Yang M, Yang N, Li Z, Duan Y. Phenotypic Selection in Halenia elliptica D. Don (Gentianaceae), an Alpine Biennial with Mixed Mating System. PLANTS (BASEL, SWITZERLAND) 2022; 11:1488. [PMID: 35684261 PMCID: PMC9183009 DOI: 10.3390/plants11111488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/30/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022]
Abstract
The transition from outcrossing to selfing is a common evolutionary trend in flowering plants, and floral traits change significantly with the evolution of selfing. Whether or not plant traits are subjected to selection remains an open question in species with mixed mating systems. We examined phenotypic selection in two populations of Halenia elliptica with different selfing rates. We found that the pollen-ovule ratio, seed size, plant height, spur length, and pollinator visitation rate in the population with the higher selfing rate were lower than those in the population with the lower selfing rate. Selfing provides reproductive assurance for populations when pollinator service is low, and the floral traits that are associated with selfing syndrome are evident in populations with a higher selfing rate but are subjected to weak selection in each of the two populations with different selfing rates. Directional selection for an early flowering time indicated that late blooming flowers could experience a risk of seed development in alpine environments, and for large plants, selection indicated that seed production could be limited by the available resources. The floral traits that are associated with pollinator attraction and specialization could be subjected to weak selection at the plant level as selfing evolves, and the selective pressures that are independent of pollinators might not change significantly; highlighting the selective biotic and abiotic pressures that shape the morphological traits of plant species and their independence from the mating system.
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Affiliation(s)
- Xiaojuan Huang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China;
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (M.C.); (L.W.); (N.Y.)
| | - Minyu Chen
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (M.C.); (L.W.); (N.Y.)
| | - Linlin Wang
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (M.C.); (L.W.); (N.Y.)
| | - Mingliu Yang
- School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China;
| | - Nacai Yang
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (M.C.); (L.W.); (N.Y.)
| | - Zhonghu Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China;
| | - Yuanwen Duan
- The Germplasm Bank of Wild Species, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (M.C.); (L.W.); (N.Y.)
- Yunnan Lijiang Forest Ecosystem National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang 674100, China
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Cisternas‐Fuentes A, Jogesh T, Broadhead GT, Raguso RA, Skogen KA, Fant JB. Evolution of selfing syndrome and its influence on genetic diversity and inbreeding: A range-wide study in Oenothera primiveris. AMERICAN JOURNAL OF BOTANY 2022; 109:789-805. [PMID: 35596689 PMCID: PMC9320852 DOI: 10.1002/ajb2.1861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 06/15/2023]
Abstract
PREMISE To avoid inbreeding depression, plants have evolved diverse breeding systems to favor outcrossing, such as self-incompatibility. However, changes in biotic and abiotic conditions can result in selective pressures that lead to a breakdown in self-incompatibility. The shift to increased selfing is commonly associated with reduced floral features, lower attractiveness to pollinators, and increased inbreeding. We tested the hypothesis that the loss of self-incompatibility, a shift to self-fertilization (autogamy), and concomitant evolution of the selfing syndrome (reduction in floral traits associated with cross-fertilization) will lead to increased inbreeding and population differentiation in Oenothera primiveris. Across its range, this species exhibits a shift in its breeding system and floral traits from a self-incompatible population with large flowers to self-compatible populations with smaller flowers. METHODS We conducted a breeding system assessment, evaluated floral traits in the field and under controlled conditions, and measured population genetic parameters using RADseq data. RESULTS Our results reveal a bimodal transition to the selfing syndrome from the west to the east of the range of O. primiveris. This shift includes variation in the breeding system and the mating system, a reduction in floral traits (flower diameter, herkogamy, and scent production), a shift to greater autogamy, reduced genetic diversity, and increased inbreeding. CONCLUSIONS The observed variation highlights the importance of range-wide studies to understand breeding system variation and the evolution of the selfing syndrome within populations and species.
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Affiliation(s)
- Anita Cisternas‐Fuentes
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
- Department of Biological ScienceClemson University132 Long HallClemsonSouth Carolina29631USA
| | - Tania Jogesh
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
| | - Geoffrey T. Broadhead
- Department of Entomology and NematologyUniversity of Florida1881 Natural Area DriveGainesvilleFlorida32611USA
| | - Robert A. Raguso
- Department of Neurobiology and BehaviorCornell UniversityW361 Mudd HallIthacaNew York14853USA
| | - Krissa A. Skogen
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
| | - Jeremie B. Fant
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
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Liao IT, Rifkin JL, Cao G, Rausher MD. Modularity and selection of nectar traits in the evolution of the selfing syndrome in Ipomoea lacunosa (Convolvulaceae). THE NEW PHYTOLOGIST 2022; 233:1505-1519. [PMID: 34783034 DOI: 10.1111/nph.17863] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Although the evolution of the selfing syndrome often involves reductions in floral size, pollen and nectar, few studies of selfing syndrome divergence have examined nectar. We investigate whether nectar traits have evolved independently of other floral size traits in the selfing syndrome, whether nectar traits diverged due to drift or selection, and the extent to which quantitative trait locus (QTL) analyses predict genetic correlations. We use F5 recombinant inbred lines (RILs) generated from a cross between Ipomoea cordatotriloba and Ipomoea lacunosa. We calculate genetic correlations to identify evolutionary modules, test whether trait divergence was due to selection, identify QTLs and perform correlation analyses to evaluate how well QTL properties reflect genetic correlations. Nectar and floral size traits form separate evolutionary modules. Selection has acted to reduce nectar traits in the selfing I. lacunosa. Genetic correlations predicted from QTL properties are consistent with observed genetic correlations. Changes in floral traits associated with the selfing syndrome reflect independent evolution of at least two evolutionary modules: nectar and floral size traits. We also demonstrate directional selection on nectar traits, which is likely to be independent of selection on floral size traits. Our study also supports the expected mechanistic link between QTL properties and genetic correlations.
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Affiliation(s)
- Irene T Liao
- Department of Biology, Duke University, Durham, NC, 27708, USA
- Department of Molecular, Cell, and Developmental Biology, University of California - Los Angeles, Los Angeles, CA, 90095, USA
| | - Joanna L Rifkin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Gongyuan Cao
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Mark D Rausher
- Department of Biology, Duke University, Durham, NC, 27708, USA
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Rifkin JL, Cao G, Rausher MD. Genetic architecture of divergence: the selfing syndrome in Ipomoea lacunosa. AMERICAN JOURNAL OF BOTANY 2021; 108:2038-2054. [PMID: 34648660 DOI: 10.1002/ajb2.1749] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Highly selfing plant species frequently display a distinctive suite of traits termed the selfing syndrome. Here we tested the hypothesis that these traits are grouped into correlated evolutionary modules and determined the degree of independence between such modules. METHODS We evaluated phenotypic correlations and QTL overlaps in F2 offspring of a cross between the morning glories Ipomoea lacunosa and I. cordatotriloba and investigated how traits clustered into modules at both the phenotypic and genetic level. We then compared our findings to other QTL studies of the selfing syndrome. RESULTS In the I. lacunosa selfing syndrome, traits grouped into modules that displayed correlated evolution within but not between modules. QTL overlap predicted phenotypic correlations, and QTLs affecting the same trait module were significantly physically clustered in the genome. The genetic architecture of the selfing syndrome varied across systems, but the pattern of stronger within- than between-module correlation was widespread. CONCLUSIONS The genetic architecture we observe in the selfing syndrome is consistent with a growing understanding of floral morphological integration achieved via pleiotropy in clustered traits. This view of floral evolution is consistent with resource limitation or predation driving the evolution of the selfing syndrome, but invites further research into both the selective causes of the selfing syndrome and how genetic architecture itself evolves in response to changes in mating system.
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Affiliation(s)
- Joanna L Rifkin
- Department of Ecology and Evolutionary Biology, The University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Gongyuan Cao
- Department of Biology, Duke University, 124 Science Drive, Durham, NC, 27701, USA
| | - Mark D Rausher
- Department of Biology, Duke University, 124 Science Drive, Durham, NC, 27701, USA
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Frazee LJ, Rifkin J, Maheepala DC, Grant AG, Wright S, Kalisz S, Litt A, Spigler R. New genomic resources and comparative analyses reveal differences in floral gene expression in selfing and outcrossing Collinsia sister species. G3 (BETHESDA, MD.) 2021; 11:jkab177. [PMID: 34014319 PMCID: PMC8496223 DOI: 10.1093/g3journal/jkab177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/11/2021] [Indexed: 11/14/2022]
Abstract
The evolutionary transition from outcross- to self-fertilization is one of the most common in angiosperms and is often associated with a parallel shift in floral morphological and developmental traits, such as reduced flower size and pollen to ovule ratios, known as the "selfing syndrome." How these convergent phenotypes arise, the extent to which they are shaped by selection, and the nature of their underlying genetic basis are unsettled questions in evolutionary biology. The genus Collinsia (Plantaginaceae) includes seven independent transitions from outcrossing or mixed mating to high selfing rates accompanied by selfing syndrome traits. Accordingly, Collinsia represents an ideal system for investigating this parallelism, but requires genomic resource development. We present a high quality de novo genome assembly for the highly selfing species Collinsia rattanii. To begin addressing the basis of selfing syndrome developmental shifts, we evaluate and contrast patterns of gene expression from floral transcriptomes across three stages of bud development for C. rattanii and its outcrossing sister species Collinsia linearis. Relative to C. linearis, total gene expression is less variable among individuals and bud stages in C. rattanii. In addition, there is a common pattern among differentially expressed genes: lower expression levels that are more constant across bud development in C. rattanii relative to C. linearis. Transcriptional regulation of enzymes involved in pollen formation specifically in early bud development may influence floral traits that distinguish selfing and outcrossing Collinsia species through pleiotropic functions. Future work will include additional Collinsia outcrossing-selfing species pairs to identify genomic signatures of parallel evolution.
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Affiliation(s)
- Lauren J Frazee
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
| | - Joanna Rifkin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S, Canada
| | - Dinusha C Maheepala
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Alannie-Grace Grant
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Stephen Wright
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S, Canada
| | - Susan Kalisz
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Amy Litt
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Rachel Spigler
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
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Selvaraj D, Velvizhi G. Sustainable ecological engineering systems for the treatment of domestic wastewater using emerging, floating and submerged macrophytes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 286:112253. [PMID: 33711758 DOI: 10.1016/j.jenvman.2021.112253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/05/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
Water scarcity is perceived as a global systemic risk since there is an inexorable rise in water demand. An ecological engineering system mimics a natural ecosystem by balancing the trophic conditions for effective treatment of wastewater in a sequential manner. The present study was designed using emergent, floating and submerged macrophytic plants in a systematic approach. The study was evaluated with several components such as plants (water hyacinth, water lettuce and water thymes), aeration (supply of oxygen), and physical adsorption (activated carbon). Domestic wastewater collected from the local effluent treatment plant was treated individually and by combining all the components. Diverse experimental setups viz., lake sediment (control reactor), aeration, activated carbon blocks, water hyacinth, water lettuce, and water thymes were individually studied. Further the above components were combined, such as lake sediment + aeration + activated carbon blocks with plants like water hyacinth, water lettuce, and water thymes. The study inferred along with phytoremediation, and the external factors enhanced the treatment performances. Water hyacinth documented enhanced chemical oxygen demand removal efficiency of 85.71%, followed by water lettuce (80%), and water thymes (77.14%) along with the plants, both aeration, and activated carbon had stimulated the wastewater treatment. The highest removal efficiency of nitrate (70.23%), phosphate (63.64%), and sulphate (61.16%) were observed in water hyacinth due to its thick roots, and fibrous tissues reported effective treatment. The study hypothesized that these processes could be an effective strategy to restore the lakes and regulate the environmental flow. The study infers that an ecological engineering system symbiotically enables to self-organize the ecosystem within the boundary.
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Affiliation(s)
- Dharanidharan Selvaraj
- School of Civil Engineering, Vellore Institute of Technology, Vellore, India; CO(2) Research & Green Technologies Centre, Vellore Institute of Technology, Vellore, India
| | - G Velvizhi
- CO(2) Research & Green Technologies Centre, Vellore Institute of Technology, Vellore, India.
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Ostevik KL, Rifkin JL, Xia H, Rausher MD. Morning glory species co-occurrence is associated with asymmetrically decreased and cascading reproductive isolation. Evol Lett 2020; 5:75-85. [PMID: 33552537 PMCID: PMC7857285 DOI: 10.1002/evl3.205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/04/2020] [Accepted: 10/19/2020] [Indexed: 01/25/2023] Open
Abstract
Hybridization between species can affect the strength of the reproductive barriers that separate those species. Two extensions of this effect are (1) the expectation that asymmetric hybridization or gene flow will have asymmetric effects on reproductive barrier strength and (2) the expectation that local hybridization will affect only local reproductive barrier strength and could therefore alter within‐species compatibility. We tested these hypotheses in a pair of morning glory species that exhibit asymmetric gene flow from highly selfing Ipomoea lacunosa into mixed‐mating Ipomoea cordatotriloba in regions where they co‐occur. Because of the direction of this gene flow, we predicted that reproductive barrier strength would be more strongly affected in I. cordatotriloba than I. lacunosa. We also predicted that changes to reproductive barriers in sympatric I. cordatotriloba populations would affect compatibility with allopatric populations of that species. We tested these predictions by measuring the strength of a reproductive barrier to seed set across the species’ ranges. Consistent with our first prediction, we found that sympatric and allopatric I. lacunosa produce the same number of seeds in crosses with I. cordatotriloba, whereas crosses between sympatric I. cordatotriloba and I. lacunosa are more successful than crosses between allopatric I. cordatotriloba and I. lacunosa. This difference in compatibility appears to reflect an asymmetric decrease in the strength of the barrier to seed set in sympatric I. cordatotriloba, which could be caused by I. lacunosa alleles that have introgressed into I. cordatotriloba. We further demonstrated that changes to sympatric I. cordatotriloba have decreased its ability to produce seeds with allopatric populations of the same species, in line with our second prediction. Thus, in a manner analogous to cascade reinforcement, we suggest that introgression associated with hybridization not only influences between‐species isolation but can also contribute to isolation within a species.
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Affiliation(s)
- Kate L Ostevik
- Department of Biology Duke University Durham North Carolina 27708
| | - Joanna L Rifkin
- Department of Ecology and Evolutionary Biology University of Toronto Toronto ON M5S 3B2 Canada
| | - Hanhan Xia
- College of Horticulture and Landscape Architecture Zhongkai University of Agriculture and Engineering Guangzhou 510225 China
| | - Mark D Rausher
- Department of Biology Duke University Durham North Carolina 27708
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Duncan TM, Rausher MD. Selection favors loss of floral pigmentation in a highly selfing morning glory. PLoS One 2020; 15:e0231263. [PMID: 32282839 PMCID: PMC7153891 DOI: 10.1371/journal.pone.0231263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/19/2020] [Indexed: 11/18/2022] Open
Abstract
A common evolutionary trend in highly selfing plants is the evolution of the “selfing syndrome”, in which traits associated with pollinator attraction are lost or greatly reduced. Limited information is available on whether these trait reductions are favored by natural selection or result from reduced purifying selection coupled with genetic drift. This study attempted to distinguish between these two possibilities for the evolutionary loss of floral pigmentation in the highly selfing species Ipomoea lacunosa. This study also tested the hypothesis that loss of floral pigmentation is caused by downregulation or loss of function in a tissue-specific anthocyanin transcription factor, as has been found in other plants. F2 individuals of a cross between white and pigmented individuals revealed segregation at two epistatically acting loci: one affecting pigmentation in both corolla throat and limbs (Anl1) and one affecting limb pigmentation (Anl2). Individuals that are homozygous for the “white” allele at Anl1 have white throats and limbs regardless of genotype at Anl2. In individuals with pigmented throats, homozygosity of the “white” allele at Anl2 produces white limbs. Flower color variation at Anl1 cosegregates with an R2R3-Myb anthocyanin transcription factor, which is down-regulated in white-flowers but not in pigmented flowers. Differential expression of the two alleles of this gene indicates that down regulation is caused by a cis-regulatory change. Finally, allele-frequency differences at Anl1 were substantially and significantly greater than differences in allele frequencies at four microsatellite loci. These results are consistent with the hypotheses that the identified R2R3-Myb gene corresponds to Anl1 and that evolutionary loss of pigmentation in I. lacunosa was caused by selection. They are also consistent with previous studies demonstrating that loss of floral pigmentation is usually caused by down-regulation or functional inactivation of an R2R3-Myb gene.
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Affiliation(s)
- Tanya M. Duncan
- Department of Biology, Duke University, Durham, NC, United States of America
| | - Mark D. Rausher
- Department of Biology, Duke University, Durham, NC, United States of America
- * E-mail:
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Scossa F, Fernie AR. The evolution of metabolism: How to test evolutionary hypotheses at the genomic level. Comput Struct Biotechnol J 2020; 18:482-500. [PMID: 32180906 PMCID: PMC7063335 DOI: 10.1016/j.csbj.2020.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 01/21/2023] Open
Abstract
The origin of primordial metabolism and its expansion to form the metabolic networks extant today represent excellent systems to study the impact of natural selection and the potential adaptive role of novel compounds. Here we present the current hypotheses made on the origin of life and ancestral metabolism and present the theories and mechanisms by which the large chemical diversity of plants might have emerged along evolution. In particular, we provide a survey of statistical methods that can be used to detect signatures of selection at the gene and population level, and discuss potential and limits of these methods for investigating patterns of molecular adaptation in plant metabolism.
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Affiliation(s)
- Federico Scossa
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
- Council for Agricultural Research and Economics (CREA), Research Centre for Genomics and Bioinformatics (CREA-GB), Via Ardeatina 546, 00178 Rome, Italy
| | - Alisdair R. Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
- Center of Plant Systems Biology and Biotechnology (CPSBB), Plovdiv, Bulgaria
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