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Aranda-Rickert A, Torréns J, Yela NI, Brizuela MM, Di Stilio VS. Distance Dependent Contribution of Ants to Pollination but Not Defense in a Dioecious, Ambophilous Gymnosperm. FRONTIERS IN PLANT SCIENCE 2021; 12:722405. [PMID: 34567036 PMCID: PMC8459830 DOI: 10.3389/fpls.2021.722405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Dioecious plants are obligate outcrossers with separate male and female individuals, which can result in decreased seed set with increasing distance between the sexes. Wind pollination is a common correlate of dioecy, yet combined wind and insect pollination (ambophily) could be advantageous in compensating for decreased pollen flow to isolated females. Dioecious, ambophilous gymnosperms Ephedra (Gnetales) secrete pollination drops (PDs) in female cones that capture airborne pollen and attract ants that feed on them. Plant sugary secretions commonly reward ants in exchange for indirect plant defense against herbivores, and more rarely for pollination. We conducted field experiments to investigate whether ants are pollinators and/or plant defenders of South American Ephedra triandra, and whether their contribution to seed set and seed cone protection varies with distance between female and male plants. We quantified pollen flow in the wind and assessed the effectiveness of ants as pollinators by investigating their relative contribution to seed set, and their visitation rate in female plants at increasing distance from the nearest male. Ants accounted for most insect visits to female cones of E. triandra, where they consumed PDs, and pollen load was larger on bigger ants without reduction in pollen viability. While wind pollination was the main contributor to seed set overall, the relative contribution of ants was distance dependent. Ant contribution to seed set was not significant at shorter distances, yet at the farthest distance from the nearest male (23 m), where 20 times less pollen reached females, ants enhanced seed set by 30% compared to plants depending solely on wind pollination. We found no evidence that ants contribute to plant defense by preventing seed cone damage. Our results suggest that, despite their short-range movements, ants can offset pollen limitation in isolated females of wind-pollinated plants with separate sexes. We propose that ants enhance plant reproductive success via targeted delivery of airborne pollen, through frequent contact with ovule tips while consuming PDs. Our study constitutes the first experimental quantification of distance-dependent contribution of ants to pollination and provides a working hypothesis for ambophily in other dioecious plants lacking pollinator reward in male plants.
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Affiliation(s)
- Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - Javier Torréns
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
| | - Natalia I. Yela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - María Magdalena Brizuela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
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A Review of the Ephedra genus: Distribution, Ecology, Ethnobotany, Phytochemistry and Pharmacological Properties. Molecules 2020; 25:molecules25143283. [PMID: 32698308 PMCID: PMC7397145 DOI: 10.3390/molecules25143283] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022] Open
Abstract
Ephedra is one of the largest genera of the Ephedraceae family, which is distributed in arid and semiarid regions of the world. In the traditional medicine from several countries some species from the genus are commonly used to treat asthma, cold, flu, chills, fever, headache, nasal congestion, and cough. The chemical constituents of Ephedra species have been of research interest for decades due to their contents of ephedrine-type alkaloids and its pharmacological properties. Other chemical constituents such as phenolic and amino acid derivatives also have resulted attractive and have provided evidence-based supporting of the ethnomedical uses of the Ephedra species. In recent years, research has been expanded to explore the endophytic fungal diversity associated to Ephedra species, as well as, the chemical constituents derived from these fungi and their pharmacological bioprospecting. Two additional aspects that illustrate the chemical diversity of Ephedra genus are the chemotaxonomy approaches and the use of ephedrine-type alkaloids as building blocks in organic synthesis. American Ephedra species, especially those that exist in Mexico, are considered to lack ephedrine type alkaloids. In this sense, the phytochemical study of Mexican Ephedra species is a promising area of research to corroborate their ephedrine-type alkaloids content and, in turn, discover new chemical compounds with potential biological activity. Therefore, the present review represents a key compilation of all the relevant information for the Ephedra genus, in particular the American species, the species distribution, their ecological interactions, its ethnobotany, its phytochemistry and their pharmacological activities and toxicities, in order to promote clear directions for future research.
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Mironov VL, Kondratev AY, Mironova AV. Growth of Sphagnum is strongly rhythmic: contribution of the seasonal, circalunar and third components. PHYSIOLOGIA PLANTARUM 2020; 168:765-776. [PMID: 31613995 DOI: 10.1111/ppl.13037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/06/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Victor L Mironov
- Institute of Biology of Karelian Research Centre RAS, Pushkinskaya st. 11, Petrozavodsk, 185910, Russia
| | - Aleksei Y Kondratev
- National Research University Higher School of Economics, Soyuza Pechatnikov st. 16, St. Petersburg, 190121, Russia
- Institute for Regional Economic Studies RAS, Serpuhovskaya st. 38, St. Petersburg, 190013, Russia
| | - Anna V Mironova
- Tsitsin Main Botanical Garden RAS, Botanicheskaya st. 4, Moscow, 127276, Russia
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Hou C, Saunders RMK, Deng N, Wan T, Su Y. Pollination Drop Proteome and Reproductive Organ Transcriptome Comparison in Gnetum Reveals Entomophilous Adaptation. Genes (Basel) 2019; 10:genes10100800. [PMID: 31614866 PMCID: PMC6826882 DOI: 10.3390/genes10100800] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/30/2019] [Accepted: 10/11/2019] [Indexed: 11/16/2022] Open
Abstract
Gnetum possesses morphologically bisexual but functionally unisexual reproductive structures that exude sugary pollination drops to attract insects. Previous studies have revealed that the arborescent species (G. gnemon L.) and the lianoid species (G. luofuense C.Y.Cheng) possess different pollination syndromes. This study compared the proteome in the pollination drops of these two species using label-free quantitative techniques. The transcriptomes of fertile reproductive units (FRUs) and sterile reproductive units (SRUs) for each species were furthermore compared using Illumina Hiseq sequencing, and integrated proteomic and transcriptomic analyses were subsequently performed. Our results show that the differentially expressed proteins between FRUs and SRUs were involved in carbohydrate metabolism, the biosynthesis of amino acids and ovule defense. In addition, the differentially expressed genes between the FRUs and SRUs (e.g., MADS-box genes) were engaged in reproductive development and the formation of pollination drops. The integrated protein-transcript analyses revealed that FRUs and their exudates were relatively conservative while the SRUs and their exudates were more diverse, probably functioning as pollinator attractants. The evolution of reproductive organs appears to be synchronized with changes in the pollination drop proteome of Gnetum, suggesting that insect-pollinated adaptations are not restricted to angiosperms but also occur in gymnosperms.
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Affiliation(s)
- Chen Hou
- School of Life Sciences, Sun Yat-Sen University, Xingangxi Road No. 135, Guangzhou 510275, China.
| | - Richard M K Saunders
- Division of Ecology & Biodiversity, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
| | - Nan Deng
- Institute of Ecology, Hunan Academy of Forestry, Shaoshannan Road, No. 6581, Changsha 410004, China.
- Hunan Cili Forest Ecosystem State Research Station, Cili 427200, China.
| | - Tao Wan
- Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Science, Liantangxianhu Road, No. 160, Shenzhen 518004, China.
- Sino-Africa Joint Research Centre, Chinese Academy of Science, Moshan, Wuhan 430074, China.
| | - Yingjuan Su
- School of Life Sciences, Sun Yat-Sen University, Xingangxi Road No. 135, Guangzhou 510275, China.
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von Aderkas P, Prior NA, Little SA. The Evolution of Sexual Fluids in Gymnosperms From Pollination Drops to Nectar. FRONTIERS IN PLANT SCIENCE 2018; 9:1844. [PMID: 30619413 PMCID: PMC6305574 DOI: 10.3389/fpls.2018.01844] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/28/2018] [Indexed: 05/23/2023]
Abstract
A current synthesis of data from modern and fossil plants paints a new picture of sexual fluids, including nectar, as a foundational component of gymnosperm reproductive evolution. We review the morpho-anatomical adaptations, their accompanying secretions, and the functional compounds involved. We discuss two types of secretions: (1) those involved in fertilization fluids produced by gametophytes and archegonia of zooidogamous gymnosperms, i.e., Ginkgo and cycads, and (2) those involved in pollen capture mechanisms (PCMs), i.e., pollination drops. Fertilization fluids provide both liquid in which sperm swim, as well as chemotactic signals that direct sperm to the egg. Such fertilization fluids were probably found among many extinct plants such as ancient cycads and others with swimming sperm, but were subsequently lost upon the evolution of siphonogamy (direct delivery of sperm to the egg by pollen tubes), as found in modern gnetophytes, conifers, and Pinaceae. Pollination drops are discussed in terms of three major types of PCMs and the unique combinations of morphological and biochemical adaptations that define each. These include their amino acids, sugars, calcium, phosphate and proteins. The evolution of PCMs is also discussed with reference to fossil taxa. The plesiomorphic state of extant gymnosperms is a sugar-containing pollination drop functioning as a pollen capture surface, and an in ovulo pollen germination medium. Additionally, these drops are involved in ovule defense, and provide nectar for pollinators. Pollination drops in anemophilous groups have low sugar concentrations that are too low to provide insects with a reward. Instead, they appear to be optimized for defense and microgametophyte development. In insect-pollinated modern Gnetales a variety of tissues produce sexual fluids that bear the biochemical signature of nectar. Complete absence of fluid secretions is restricted to a few, poorly studied modern conifers, and is presumably derived. Aspects of pollination drop dynamics, e.g., regulation of secretion and retraction, are reviewed. Lastly, we discuss pollination drops' control of pollen germination. Large gaps in our current knowledge include the composition of fertilization fluids, the pollination drops of Podocarpaceae, and the overall hydrodynamics of sexual fluids in general.
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Walas Ł, Mandryk W, Thomas PA, Tyrała-Wierucka Ż, Iszkuło G. Sexual systems in gymnosperms: A review. Basic Appl Ecol 2018. [DOI: 10.1016/j.baae.2018.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nepi M, Little S, Guarnieri M, Nocentini D, Prior N, Gill J, Barry Tomlinson P, Ickert-Bond SM, Pirone C, Pacini E, von Aderkas P. Phylogenetic and functional signals in gymnosperm ovular secretions. ANNALS OF BOTANY 2017; 120:923-936. [PMID: 29045531 PMCID: PMC5710648 DOI: 10.1093/aob/mcx103] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/02/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Gymnosperms are either wind-pollinated (anemophilous) or both wind- and insect-pollinated (ambophilous). Regardless of pollination mode, ovular secretions play a key role in pollen capture, germination and growth; they are likely also involved in pollinator reward. Little is known about the broad-scale diversity of ovular secretions across gymnosperms, and how these may relate to various reproductive functions. This study analyses the sugar and amino acid profiles of ovular secretions across a range of ambophilous (cycads and Gnetales) and anemophilous gymnosperms (conifers) to place them in an evolutionary context of their possible functions during reproduction. METHODS Ovular secretions from 13 species representing all five main lineages of extant gymnosperms were sampled. High-performance liquid chromatography techniques were used to measure sugar and amino acid content. Multivariate statistics were applied to assess whether there are significant differences in the chemical profiles of anemophilous and ambophilous species. Data were compared with published chemical profiles of angiosperm nectar. Chemical profiles were placed in the context of phylogenetic relationships. KEY RESULTS Total sugar concentrations were significantly higher in ovular secretions of ambophilous species than wind-pollinated taxa such as Pinaceae and Cupressophyta. Ambophilous species had lower amounts of total amino acids, and a higher proportion of non-protein amino acids compared with anemophilous lineages, and were also comparable to angiosperm nectar. Results suggest that early gymnosperms likely had ovular secretion profiles that were a mosaic of those associated with modern anemophilous and ambophilous species. Ginkgo, thought to be anemophilous, had a profile typical of ambophilous taxa, suggesting that insect pollination either exists in Gingko, but is undocumented, or that its ancestral populations were insect-pollinated. CONCLUSIONS Chemical profiles of ovular secretions of ambophilous gymnosperms show a clear signal of pollinator-driven selection, including higher levels of carbohydrates than anemophilous taxa, lower levels of amino acids, and the presence of specific amino acids, such as β-alanine, that are known to influence insect feeding behaviour and physiology.
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Affiliation(s)
- Massimo Nepi
- Department of Life Sciences, University of Siena, Siena, Italy
- For correspondence. E-mail:
| | - Stefan Little
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, BC, Canada
- Laboratoire Écologie, Systématique, Évolution, CNRS UMR 8079, Université Paris-Sud, Orsay, France
| | | | | | - Natalie Prior
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Julia Gill
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, BC, Canada
| | | | - Stefanie M Ickert-Bond
- UA Museum of the North and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Cary Pirone
- The Arnold Arboretum of Harvard University, Boston, MA, USA
| | - Ettore Pacini
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Patrick von Aderkas
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, BC, Canada
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Meena B, Tiwari V, Singh N, Mahar KS, Sharma YK, Rana TS. Estimation of genetic variability and population structure in Ephedra gerardiana Wall. ex Stapf (Ephedraceae): An endangered and endemic high altitude medicinal plant. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.aggene.2016.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lora J, Hormaza JI, Herrero M. The Diversity of the Pollen Tube Pathway in Plants: Toward an Increasing Control by the Sporophyte. FRONTIERS IN PLANT SCIENCE 2016; 7:107. [PMID: 26904071 PMCID: PMC4746263 DOI: 10.3389/fpls.2016.00107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/20/2016] [Indexed: 05/06/2023]
Abstract
Plants, unlike animals, alternate multicellular diploid, and haploid generations in their life cycle. While this is widespread all along the plant kingdom, the size and autonomy of the diploid sporophyte and the haploid gametophyte generations vary along evolution. Vascular plants show an evolutionary trend toward a reduction of the gametophyte, reflected both in size and lifespan, together with an increasing dependence from the sporophyte. This has resulted in an overlooking of the importance of the gametophytic phase in the evolution of higher plants. This reliance on the sporophyte is most notorious along the pollen tube journey, where the male gametophytes have to travel a long way inside the sporophyte to reach the female gametophyte. Along evolution, there is a change in the scenery of the pollen tube pathway that favors pollen competition and selection. This trend, toward apparently making complicated what could be simple, appears to be related to an increasing control of the sporophyte over the gametophyte with implications for understanding plant evolution.
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Affiliation(s)
- Jorge Lora
- Department of Subtropical Fruit Crops, Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora – University of Málaga – Consejo Superior de Investigaciones CientíficasMálaga, Spain
| | - José I. Hormaza
- Department of Subtropical Fruit Crops, Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora – University of Málaga – Consejo Superior de Investigaciones CientíficasMálaga, Spain
| | - María Herrero
- Department of Pomology, Estación Experimental Aula Dei, Consejo Superior de Investigaciones CientíficasZaragoza, Spain
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Hou C, Wikström N, Rydin C. The chloroplast genome of Ephedra foeminea (Ephedraceae, Gnetales), an entomophilous gymnosperm endemic to the Mediterranean area. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 28:330-331. [PMID: 26713841 DOI: 10.3109/19401736.2015.1122768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study presents the chloroplast genome of Ephedra foeminea, an entomophilous gymnosperm, sister to the remaining (wind-pollinated) species of Ephedra (Ephedraceae, Gnetales). Based on the reference-guided assembly, the length of the chloroplast genome was estimated to be 109 584 bp, comprising a large single copy region of 60 027 bp, a small single copy 8079 bp, and inverted repeat regions of 20 739 bp. In total, 118 genes were detected, including 73 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The gene density is 1.076 (genes/kb) and the GC content is 36.7%. The genomic sequence of the entomophilous, Mediterranean species E. foeminea, differs from that of the anemophilous, Asian species E. equisetina by 1018 point mutations and 1334 indels. The detected variation is useful for future development of new plastid markers for phylogenetic purposes. Our phylogenetic analysis based on 55 protein-coding chloroplast genes resolve Ephedra as monophyletic and sister to a Gnetum-Welwitschia clade. The Gnetales are sister to Cupressophytes.
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Affiliation(s)
- Chen Hou
- a Department of Ecology, Environment and Plant Sciences , Stockholm University , Stockholm , Sweden
| | - Niklas Wikström
- b Bergius Foundation, the Royal Swedish Academy of Sciences and Department of Ecology, Environment and Plant Sciences , Stockholm University , Stockholm , Sweden
| | - Catarina Rydin
- b Bergius Foundation, the Royal Swedish Academy of Sciences and Department of Ecology, Environment and Plant Sciences , Stockholm University , Stockholm , Sweden
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