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Liu Z, Michalet R, Wang C, Wang Y, Chen J, Cui H, Song H, Wang J, Yang Z, An L, Xiao S, Chen S. Contrasting effects of two phenotypes of an alpine cushion plant on understory species drive community assembly. Sci Total Environ 2023; 859:160154. [PMID: 36375548 DOI: 10.1016/j.scitotenv.2022.160154] [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: 07/02/2022] [Revised: 10/24/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
In alpine systems, cushion plants act as foundation species by ameliorating local environmental conditions. Empirical studies indicate that contrasting phenotypes of alpine cushion species have different effects on understory plant species, either facilitative or competitive. Furthermore, dependent species within each community type might also exhibit different responses to each cushion phenotype, which can be clustered into several "response groups". Additionally, these species-groups specific responses to alpine cushion species phenotypes could alter community assembly. However, very few studies have assessed responses of dependent communities at species-group levels, in particular for both above- and below-ground communities. Here, we selected a loose and a tight phenotype of the alpine cushion species Thylacospermum caespitosum in two sites of northwest China, and use the relative intensity of interactions index to quantify cushion plant effects on subordinate communities of plants and soil fungi and bacteria. We assessed variations in responses of both above- and below-ground organisms to cushion plant effects at species-group level. Species-group level analyses showed that the effects of the phenotype varied among groups of each of the three community types, and different species-groups were composed by unique taxa. Additionally, we found that loose cushions enhanced stochastic processes in community assembly, for plants and soil fungi but not for soil bacteria. These variations of phenotypic effects on different species-group induced contrasting taxonomic composition between groups, and alter community assembly thereby. Our study highlights the occurrence of contrasting effects of two phenotypes of a foundation cushion plant on understory plants, soil fungi and bacteria community composition, but not necessarily on their richness. We also showed that assessing responses of understory species at the species-group level allows a more realistic and mechanistic understanding of biotic interactions both for above- and below-ground communities.
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Affiliation(s)
- Ziyang Liu
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Richard Michalet
- Environnements et Paléoenvironnements Océaniques et Continentaux, University of Bordeaux, Bordeaux, France
| | - Chenyue Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Yajun Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Jingwei Chen
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Hanwen Cui
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Hongxian Song
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Jiajia Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Zi Yang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Lizhe An
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Sa Xiao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Shuyan Chen
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China.
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Behroozian M, Ejtehadi H, Peterson AT, Memariani F, Mesdaghi M. Climate change influences on the potential distribution of Dianthus polylepis Bien. ex Boiss. (Caryophyllaceae), an endemic species in the Irano-Turanian region. PLoS One 2020; 15:e0237527. [PMID: 32810170 PMCID: PMC7437464 DOI: 10.1371/journal.pone.0237527] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/28/2020] [Indexed: 11/19/2022] Open
Abstract
Endemic and restricted-range species are considered to be particularly vulnerable to the effects of environmental change, which makes assessing likely climate change effects on geographic distributions of such species important to the development of integrated conservation strategies. Here, we determined distributional patterns for an endemic species of Dianthus (Dianthus polylepis) in the Irano-Turanian region using a maximum-entropy algorithm. In total, 70 occurrence points and 19 climatic variables were used to estimate the potential distributional area under current conditions and two future representative concentration pathway (RCP2.6 and RCP8.5) scenarios under seven general circulation models for 2050. Mean diurnal range, iso-thermality, minimum temperature of coldest quarter, and annual precipitation were major factors that appeared to structure the distribution of the species. Most current potential suitable areas were located in montane regions. Model transfers to future-climate scenarios displayed upward shifts in elevation and northward shifts geographically for the species. Our results can be used to define high-priority areas in the Irano-Turanian region for conservation management plans for this species and can offer a template for analyses of other endangered and threatened species in the region.
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Affiliation(s)
- Maryam Behroozian
- Quantitative Plant Ecology and Biodiversity Research Lab., Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hamid Ejtehadi
- Quantitative Plant Ecology and Biodiversity Research Lab., Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
- * E-mail:
| | - A. Townsend Peterson
- Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America
| | - Farshid Memariani
- Department of Botany, Research Center for Plant Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mansour Mesdaghi
- Department of Range and Watershed Management, Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad, Mashhad, Iran
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Clemente-Moreno MJ, Omranian N, Sáez P, Figueroa CM, Del-Saz N, Elso M, Poblete L, Orf I, Cuadros-Inostroza A, Cavieres L, Bravo L, Fernie A, Ribas-Carbó M, Flexas J, Nikoloski Z, Brotman Y, Gago J. Cytochrome respiration pathway and sulphur metabolism sustain stress tolerance to low temperature in the Antarctic species Colobanthus quitensis. New Phytol 2020; 225:754-768. [PMID: 31489634 DOI: 10.1111/nph.16167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 05/10/2019] [Accepted: 08/22/2019] [Indexed: 05/28/2023]
Abstract
Understanding the strategies employed by plant species that live in extreme environments offers the possibility to discover stress tolerance mechanisms. We studied the physiological, antioxidant and metabolic responses to three temperature conditions (4, 15, and 23°C) of Colobanthus quitensis (CQ), one of the only two native vascular species in Antarctica. We also employed Dianthus chinensis (DC), to assess the effects of the treatments in a non-Antarctic species from the same family. Using fused LASSO modelling, we associated physiological and biochemical antioxidant responses with primary metabolism. This approach allowed us to highlight the metabolic pathways driving the response specific to CQ. Low temperature imposed dramatic reductions in photosynthesis (up to 88%) but not in respiration (sustaining rates of 3.0-4.2 μmol CO2 m-2 s-1 ) in CQ, and no change in the physiological stress parameters was found. Its notable antioxidant capacity and mitochondrial cytochrome respiratory activity (20 and two times higher than DC, respectively), which ensure ATP production even at low temperature, was significantly associated with sulphur-containing metabolites and polyamines. Our findings potentially open new biotechnological opportunities regarding the role of antioxidant compounds and respiratory mechanisms associated with sulphur metabolism in stress tolerance strategies to low temperature.
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Affiliation(s)
- María José Clemente-Moreno
- Research Group on Plant Biology under Mediterranean Conditions, Instituto de Agroecología y Economía del Agua (INAGEA), Universitat de les Illes Balears (UIB), cta. Valldemossa km 7,5, 07122, Palma de Mallorca, Spain
| | - Nooshin Omranian
- Systems Biology and Mathematical Modeling Group, Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476, Potsdam-Golm, Germany
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Patricia Sáez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, 4030000, Concepción, Chile
| | - Carlos María Figueroa
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, 3000, Santa Fe, Argentina
| | - Néstor Del-Saz
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000, Concepción, Chile
| | - Mhartyn Elso
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, 4030000, Concepción, Chile
| | - Leticia Poblete
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, 4030000, Concepción, Chile
| | - Isabel Orf
- Department of Life Sciences, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
| | | | - Lohengrin Cavieres
- ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000, Concepción, Chile
| | - León Bravo
- Laboratorio de Fisiología y Biología Molecular Vegetal, Departamento de Cs. Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Forestales, Instituto de Agroindustria, Universidad de La Frontera, Temuco, Chile
- Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, 4811230, Temuco, Chile
| | - Alisdair Fernie
- Central Metabolism Group, Molecular Physiology Department, Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476, Golm, Germany
| | - Miquel Ribas-Carbó
- Research Group on Plant Biology under Mediterranean Conditions, Instituto de Agroecología y Economía del Agua (INAGEA), Universitat de les Illes Balears (UIB), cta. Valldemossa km 7,5, 07122, Palma de Mallorca, Spain
| | - Jaume Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Instituto de Agroecología y Economía del Agua (INAGEA), Universitat de les Illes Balears (UIB), cta. Valldemossa km 7,5, 07122, Palma de Mallorca, Spain
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modeling Group, Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476, Potsdam-Golm, Germany
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
- Center of Plant System Biology and Biotechnology (CPSBB), 4000, Plovdiv, Bulgaria
| | - Yariv Brotman
- Department of Life Sciences, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
| | - Jorge Gago
- Research Group on Plant Biology under Mediterranean Conditions, Instituto de Agroecología y Economía del Agua (INAGEA), Universitat de les Illes Balears (UIB), cta. Valldemossa km 7,5, 07122, Palma de Mallorca, Spain
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Sanhueza C, Fuentes F, Cortés D, Bascunan-Godoy L, Sáez PL, Bravo LA, Cavieres LA. Contrasting thermal acclimation of leaf dark respiration and photosynthesis of Antarctic vascular plant species exposed to nocturnal warming. Physiol Plant 2019; 167:205-216. [PMID: 30467866 DOI: 10.1111/ppl.12881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/02/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Leaf respiration and photosynthesis will respond differently to an increase in temperature during night, which can be more relevant in sensitive ecosystems such as Antarctica. We postulate that the plant species able to colonize the Antarctic Peninsula - Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv. - are able to acclimate their foliar respiration and to maintain photosynthesis under nocturnal warming to sustain a positive foliar carbon balance. We conducted a laboratory experiment to evaluate the effect of time of day (day and night) and nocturnal warming on dark respiration. Short (E0 and Q10 ) and long-term acclimation of respiration, leaf carbohydrates, photosynthesis (Asat ) and foliar carbon balance (R/A) were evaluated. The results suggest that the two species have differential thermal acclimation respiration, where D. antarctica showed more thermosensitivity to short-term changes in temperature than C. quitensis. Experimental nocturnal warming affected respiration at daytime differentially between the two species, with a significant increase of R10 and Asat in D. antarctica, while no changes on respiration were observed in C. quitensis. Long thermal treatments of the plants indicated that nocturnal but not diurnal respiration could acclimate in both species, and to a greater extent in C. quitensis. Non-structural carbohydrates were related with respiration in C. quitensis but not in D. antarctica, suggesting that respiration in the former species is likely controlled by total soluble sugars and starch during day and night, respectively. Finally, foliar carbon balance was differentially improved under warming conditions in Antarctic plants by different mechanisms, with C. quitensis deploying respiratory acclimation, while D. antarctica increased its Asat.
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Affiliation(s)
- Carolina Sanhueza
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Francisca Fuentes
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - Daniela Cortés
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - Luisa Bascunan-Godoy
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
- Instituto de Investigación Multidisciplinar en Ciencia y Tecnología, Universidad de La Serena, Coquimbo, Chile
| | - Patricia L Sáez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - León A Bravo
- Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Agroindustria, Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Forestales and Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Temuco, Chile
| | - Lohengrin A Cavieres
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias de la Universidad de Chile, Instituto de Ecología y Biodiversidad-IEB, Santiago, Chile
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Valdés A, Marteinsdóttir B, Ehrlén J. A natural heating experiment: Phenotypic and genotypic responses of plant phenology to geothermal soil warming. Glob Chang Biol 2019; 25:954-962. [PMID: 30430704 DOI: 10.1111/gcb.14525] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 09/12/2018] [Accepted: 10/29/2018] [Indexed: 06/09/2023]
Abstract
Under global warming, the survival of many populations of sedentary organisms in seasonal environments will largely depend on their ability to cope with warming in situ by means of phenotypic plasticity or adaptive evolution. This is particularly true in high-latitude environments, where current growing seasons are short, and expected temperature increases large. In such short-growing season environments, the timing of growth and reproduction is critical to survival. Here, we use the unique setting provided by a natural geothermal soil warming gradient (Hengill geothermal area, Iceland) to study the response of Cerastium fontanum flowering phenology to temperature. We hypothesized that trait expression and phenotypic selection on flowering phenology are related to soil temperature, and tested the hypothesis that temperature-driven differences in selection on phenology have resulted in genetic differentiation using a common garden experiment. In the field, phenology was related to soil temperature, with plants in warmer microsites flowering earlier than plants at colder microsites. In the common garden, plants responded to spring warming in a counter-gradient fashion; plants originating from warmer microsites flowered relatively later than those originating from colder microsites. A likely explanation for this pattern is that plants from colder microsites have been selected to compensate for the shorter growing season by starting development at lower temperatures. However, in our study we did not find evidence of variation in phenotypic selection on phenology in relation to temperature, but selection consistently favoured early flowering. Our results show that soil temperature influences trait expression and suggest the existence of genetically based variation in flowering phenology leading to counter-gradient local adaptation along a gradient of soil temperatures. An important implication of our results is that observed phenotypic responses of phenology to global warming might often be a combination of short-term plastic responses and long-term evolutionary responses, acting in different directions.
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Affiliation(s)
- Alicia Valdés
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | | | - Johan Ehrlén
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
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de Luis M, Bartolomé C, García Cardo Ó, Martínez Labarga JM, Álvarez-Jiménez J. Sympatric and allopatric niche shift of endemic Gypsophila (Caryophyllaceae) taxa in the Iberian Peninsula. PLoS One 2018; 13:e0206043. [PMID: 30403709 PMCID: PMC6221283 DOI: 10.1371/journal.pone.0206043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 10/05/2018] [Indexed: 12/03/2022] Open
Abstract
Several species of the Gypsophila genus are endemic to the Iberian Peninsula, including gypsophytes of particular ecological, evolutionary and biochemical interest, and taxa that have undergone both sympatric and allopatric genetic differentiation. The niche shift among these taxa has been assessed using ecological niche modelling and ordination techniques, adopting a niche overlap approach to compare the similarity and equivalency of the ecological niches. We used the Maximum Entropy method to study the potential distribution of these taxa in different eras: the Last Glacial Maximum (LGM), the Mid Holocene and the current conditions. We present evidence of niche shift during the speciation of G. bermejoi, with a strong niche overlap between the parental taxa (G. struthium subsp. struthium and G. tomentosa), yet both overlap much more weakly with the hybrid species. This phenomenon may be explained by genetic and epigenetic interactions, and it has been described in other species. We also studied the sister subspecies G. struthium subsp. struthium and G. struthium subsp. hispanica, with mostly allopatric distributions and with the Iberian System mountain range acting as a geographical barrier. The Iberian System and other mountain ranges may have favored differences in the climatic conditions on either side of the mountain range, which is consistent with an incipient process of bioclimatic ecological speciation. These results seem to indicate that niche shift can occur over very different timespans. In the case of G. bermejoi, speciation may have produced significant niche shifting in one or two generations due to its alloploid nature. By contrast, G. struthium subsp. struthium and G. struthium subsp. hispanica seem to have undergone a more gradual process of allopatric genetic differentiation driven by bioclimatic factors. Both these processes are relatively recent and they will have been strongly influenced by the climate change at the end of LGM.
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Affiliation(s)
- Miguel de Luis
- Departamento de Ciencias de la Vida, Facultad de Ciencias, Universidad de Alcalá, Alcalá de Henares (Madrid), Spain
| | - Carmen Bartolomé
- Departamento de Ciencias de la Vida, Facultad de Ciencias, Universidad de Alcalá, Alcalá de Henares (Madrid), Spain
- * E-mail:
| | - Óscar García Cardo
- Empresa Pública de Gestión Ambiental de Castilla-La Mancha (GEACAM), Cuenca, Spain
| | - Juan Manuel Martínez Labarga
- Departamento de Sistemas y Recursos Naturales, E.T.S.I. Montes, Forestal y del Medio Natural, Universidad Politécnica de Madrid, Madrid, Spain
| | - Julio Álvarez-Jiménez
- Departamento de Ciencias de la Vida, Facultad de Ciencias, Universidad de Alcalá, Alcalá de Henares (Madrid), Spain
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Liu W, Bai S, Zhao N, Jia S, Li W, Zhang L, Wang J. Non-target site-based resistance to tribenuron-methyl and essential involved genes in Myosoton aquaticum (L.). BMC Plant Biol 2018; 18:225. [PMID: 30305027 PMCID: PMC6180388 DOI: 10.1186/s12870-018-1451-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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: 02/08/2018] [Accepted: 09/27/2018] [Indexed: 05/30/2023]
Abstract
BACKGROUND Water chickweed (Myosoton aquaticum (L.)) is a dicot broadleaf weed that is widespread in winter fields in China, and has evolved serious resistance to acetolactate synthase (ALS) inhibiting herbicides. RESULTS We identified a M. aquaticum population exhibiting moderate (6.15-fold) resistance to tribenuron-methyl (TM). Target-site ALS gene sequencing revealed no known resistance mutations in these plants, and the in vitro ALS activity assays showed no differences in enzyme sensitivity between susceptible and resistant populations; however, resistance was reversed by pretreatment with the cytochrome P450 (CYP) monooxygenase inhibitor malathion. An RNA sequencing transcriptome analysis was performed to identify candidate genes involved in metabolic resistance, and the unigenes obtained by de novo transcriptome assembly were annotated across seven databases. In total, 34 differentially expressed genes selected by digital gene expression analysis were validated by quantitative real-time (qRT)-PCR. Ten consistently overexpressed contigs, including four for CYP, four for ATP-binding cassette (ABC) transporter, and two for peroxidase were further validated by qRT-PCR using additional plants from resistant and susceptible populations. Three CYP genes (with homology to CYP734A1, CYP76C1, and CYP86B1) and one ABC transporter gene (with homology to ABCC10) were highly expressed in all resistant plants. CONCLUSION The mechanism of TM resistance in M. aquaticum is controlled by NTSR rather than TSR. Four genes, CYP734A1, CYP76C1, CYP86B1, and ABCC10 could play essential role in metabolic resistance to TM and justify further functional studies. To our knowledge, this is the first large-scale transcriptome analysis of genes associated with NTSR in M. aquaticum using the Illumina platform. Our data provide resource for M. aquaticum biology, and will facilitate the study of herbicide resistance mechanism at the molecular level in this species as well as in other weeds.
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Affiliation(s)
- Weitang Liu
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Shuang Bai
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Ning Zhao
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Sisi Jia
- Taian Customs, Taian, 271000 Shandong China
| | - Wei Li
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Lele Zhang
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Jinxin Wang
- Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Taian, 271018 Shandong China
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Zhao RM, Zhang H, An LZ. Thylacospermum caespitosum population structure and cushion species community diversity along an altitudinal gradient. Environ Sci Pollut Res Int 2018; 25:28998-29005. [PMID: 30109682 DOI: 10.1007/s11356-018-2893-2] [Citation(s) in RCA: 2] [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: 03/14/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
As alpine plants, cushion species are particularly susceptible to environment changes. Thus, understanding population structure and community diversity variation of cushion plants along elevational gradients is crucial for estimating their response to predicted climate changes. In this study, Thylacospermum caespitosum populations from three elevations (low, medium, and high) in three climate zones of China (the Kunlun, Qilian, and Tianshan Mountains) were selected to evaluate the effect of elevation on the structure of T. caespitosum populations and species diversity of cushion communities. Results showed that elevation substantially influenced T. caespitosum populations (size structure, density, and death rate), as well as richness (α-diversity) and microhabitat species pool (species pool) of cushion communities. In the low elevations, T. caespitosum populations were in decline due to a lower ratio of small plants and higher mortality compared with populations at medium and high elevations. The α-diversity and species pool in cushion communities were significantly increased with decreased elevation, but the importance value of T. caespitosum decreased accordingly. Moreover, there was a significant positive correlation between elevation and relative importance value (the importance of one species in the community) of T. caespitosum (r = 0.883; P < 0.01). Elevation was significantly negatively correlated with the mortality rate of T. caespitosum (r = - 0.855; P < 0.01), α-diversity (r = - 0.933; P < 0.001), and species pool (r = - 0.885; P < 0.01). The declining characters of T. caespitosum population structure were obvious in low elevation populations. This decline may directly or indirectly relate to environmental change. Effects of elevation can provide an early indication of range contractions and population declines of cushion species with future climate warming. We call for more mechanistic studies of climate change impacts on cushion populations, particularly in alpine systems near the snow line.
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Affiliation(s)
- Rui-Ming Zhao
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Tianshui Middle Road 18, Lanzhou, 730000, Gansu, China.
| | - Hua Zhang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road 222, Lanzhou, 730000, Gansu, China
| | - Li-Zhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road 222, Lanzhou, 730000, Gansu, China
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Li C, Shi X, Mohamad OA, Gao J, Xu X, Xie Y. Moderate irrigation intervals facilitate establishment of two desert shrubs in the Taklimakan Desert Highway Shelterbelt in China. PLoS One 2017; 12:e0180875. [PMID: 28719623 PMCID: PMC5515419 DOI: 10.1371/journal.pone.0180875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 06/22/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Water influences various physiological and ecological processes of plants in different ecosystems, especially in desert ecosystems. The purpose of this study is to investigate the response of physiological and morphological acclimation of two shrubs Haloxylon ammodendron and Calligonum mongolicunl to variations in irrigation intervals. METHODOLOGY/PRINCIPAL FINDINGS The irrigation frequency was set as 1-, 2-, 4-, 8- and 12-week intervals respectively from March to October during 2012-2014 to investigate the response of physiological and morphological acclimation of two desert shrubs Haloxylon ammodendron and Calligonum mongolicunl to variations in the irrigation system. The irrigation interval significantly affected the individual-scale carbon acquisition and biomass allocation pattern of both species. Under good water conditions (1- and 2-week intervals), carbon assimilation was significantly higher than other treatments; while, under water shortage conditions (8- and 12-week intervals), there was much defoliation; and under moderate irrigation intervals (4 weeks), the assimilative organs grew gently with almost no defoliation occurring. CONCLUSION/SIGNIFICANCE Both studied species maintained similar ecophysiologically adaptive strategies, while C. mongolicunl was more sensitive to drought stress because of its shallow root system and preferential belowground allocation of resources. A moderate irrigation interval of 4 weeks was a suitable pattern for both plants since it not only saved water but also met the water demands of the plants.
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Affiliation(s)
- Congjuan Li
- Department of National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China
| | - Xiang Shi
- Department of Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Osama Abdalla Mohamad
- Department of Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China
| | - Jie Gao
- Department of National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China
| | - Xinwen Xu
- Department of National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China
| | - Yijun Xie
- Department of Midong Municipal Bureau of Parks, Urumqi Forestry Bureau, Urumqi, Xinjiang, China
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10
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Pintó-Marijuan M, Cotado A, Fleta-Soriano E, Munné-Bosch S. Drought stress memory in the photosynthetic mechanisms of an invasive CAM species, Aptenia cordifolia. Photosynth Res 2017; 131:241-253. [PMID: 27757688 DOI: 10.1007/s11120-016-0313-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 01/05/2016] [Accepted: 09/26/2016] [Indexed: 05/12/2023]
Abstract
Plants are known for their high capacity to acclimatise to fluctuating environmental conditions. A wide range of environmental conditions can lead to suboptimal physiological efficiency. However, recent studies have shown that plants can withstand repeated periods of stress. To find out how they do it, we studied photosynthetic adjustments to repeated water stress in Aptenia cordifolia: a facultative, invasive CAM species. Plants were subjected to three cycles of water deficit, and photosynthetic parameters and chloroplast antioxidants were quantified to gain an understanding of the mechanisms by which they cope with repeated stress periods. Significant modification of the photosystems' antenna and reaction centres was observed in plants subjected to previous water stress cycles, and this led to higher PSII efficiency than in plants challenged with drought for the first time. These findings underline the biological significance of stress memory and show how plants can adjust their photosynthetic apparatus to fluctuating environmental conditions and thus optimise photosynthesis and photoprotection under drought conditions.
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Affiliation(s)
- Marta Pintó-Marijuan
- Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028, Barcelona, Spain.
| | - Alba Cotado
- Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028, Barcelona, Spain
| | - Eva Fleta-Soriano
- Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028, Barcelona, Spain
| | - Sergi Munné-Bosch
- Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, 08028, Barcelona, Spain
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11
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Weller SG, Sakai AK, Campbell DR, Powers JM, Peña SR, Keir MJ, Loomis AK, Heintzman SM, Weisenberger L. An enigmatic Hawaiian moth is a missing link in the adaptive radiation of Schiedea. New Phytol 2017; 213:1533-1542. [PMID: 28079938 DOI: 10.1111/nph.14254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 06/28/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Shifts in pollination may drive adaptive diversification of reproductive systems within plant lineages. The monophyletic genus Schiedea is a Hawaiian lineage of 32 extant species, with spectacular diversity in reproductive systems. Biotic pollination is the presumed ancestral condition, but this key element of the life history and its role in shaping reproductive systems has remained undocumented. We observed floral visitors to two species of Schiedea and conducted field experiments to test pollinator effectiveness. We used choice tests to compare attraction of pollinators to species hypothesized to be biotically vs wind-pollinated. Pseudoschrankia brevipalpis (Erebidae), a recently described moth species known only from O'ahu, visited hermaphroditic Schiedea kaalae and S. hookeri and removed nectar from their unique tubular nectary extensions. Pseudoschrankia brevipalpis effectively pollinates S. kaalae; single visits to emasculated flowers resulted in pollen transfer. In choice tests, P. brevipalpis strongly preferred these hermaphroditic species over two subdioecious species capable of wind pollination. A shift from biotic to abiotic pollination is clearly implicated in the diversification of reproductive systems within Schiedea. Abundant pollination by a previously unknown native moth in experimental and restored populations suggests the potential for restoration to re-establish native plant-pollinator interactions critical for production of outcrossed individuals with high fitness.
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Affiliation(s)
- Stephen G Weller
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Ann K Sakai
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Diane R Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - John M Powers
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Sean R Peña
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Matthew J Keir
- O'ahu Army Natural Resources Program, Pacific Cooperative Studies Unit, University of Hawai'i, Honolulu, HI 96822, USA
| | - Alexander K Loomis
- O'ahu Army Natural Resources Program, Pacific Cooperative Studies Unit, University of Hawai'i, Honolulu, HI 96822, USA
| | - Scott M Heintzman
- O'ahu Army Natural Resources Program, Pacific Cooperative Studies Unit, University of Hawai'i, Honolulu, HI 96822, USA
| | - Lauren Weisenberger
- O'ahu Army Natural Resources Program, Pacific Cooperative Studies Unit, University of Hawai'i, Honolulu, HI 96822, USA
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12
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Arizaga MV, Yamamoto SI, Tanaka D, Fukui K, Nohara N, Nishikawa T, Watanabe K, Niino T. Cryopreservation of in vitro Shoot Tips of Ulluco (Ullucus tuberosus Cal.) Using D Cryo-Plate Method. Cryo Letters 2017; 38:419-427. [PMID: 29734437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
UNLABELLED BACKGROUND: Maintenance of in vitro collections of ulluco (Ullucus tuberosus Cal.) is cumbersome and costly in an ex-situ genebank. An alternative method for long term preservation which is safe and cost-effective is required. OBJECTIVE To apply a novel cryopreservation procedure using the cryo-plate system to improve the long-term conservation of ulluco. MATERIALS AND METHODS Initially V and D cryo-plate methods were tested, subsequently the D cryo-plate method was selected for ulluco cryopreservation. The D cryo-plate procedures were optimized for post-LN regrowth procedures including cold-hardening, sucrose addition in alginate gel, and duration of LS treatment. Optimized procedures were tested with 11 ulluco lines. RESULTS Shoot tips were isolated from cold-hardened shoots for 3-4 weeks at 5 degree C were excised to 1.0-1.5 mm long and 0.5 mm wide and precultured for 16h at 25 degree C on MS with 0.3 M sucrose. The shoot tips were attached on the cryo-plates by alginate gel with 0.4M sucrose. The cryo-plates with attached shoot tips were treated with 2.0 M glycerol and 1.0 M sucrose solution for 90 min at 25 degree C and dehydrated on filter paper in a Petri dish by air current flow at 25 degree C for 45 min before direct immersion in LN. This optimized procedure was applied to shoot tips of 11 ulluco lines, resulting regrowth ranging from 73 % to 97 %, with an average of 90 % post-LN regrowth. CONCLUSION D cryo-plate is a practical and simple procedure for cryo-storage of in vitro grown ulluco shoot tips in an ex situ genebank.
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Affiliation(s)
- M V Arizaga
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba Japan
| | | | - D Tanaka
- NARO Genetic Resources Center, Tsukuba, Japan
| | - K Fukui
- NARO Genetic Resources Center, Tsukuba, Japan
| | - N Nohara
- NARO Genetic Resources Center, Tsukuba, Japan
| | - T Nishikawa
- NARO Genetic Resources Center, Tsukuba, Japan
| | - K Watanabe
- Gene Research Center, University of Tsukuba, Tsukuba, Japan
| | - T Niino
- Gene Research Center, University of Tsukuba, Tsukuba, Japan
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13
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Torres-Díaz C, Gallardo-Cerda J, Lavin P, Oses R, Carrasco-Urra F, Atala C, Acuña-Rodríguez IS, Convey P, Molina-Montenegro MA. Biological Interactions and Simulated Climate Change Modulates the Ecophysiological Performance of Colobanthus quitensis in the Antarctic Ecosystem. PLoS One 2016; 11:e0164844. [PMID: 27776181 PMCID: PMC5077106 DOI: 10.1371/journal.pone.0164844] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 10/01/2016] [Indexed: 11/18/2022] Open
Abstract
Most climate and environmental change models predict significant increases in temperature and precipitation by the end of the 21st Century, for which the current functional output of certain symbioses may also be altered. In this context we address the following questions: 1) How the expected changes in abiotic factors (temperature, and water) differentially affect the ecophysiological performance of the plant Colobanthus quitensis? and 2) Will this environmental change indirectly affect C. quitensis photochemical performance and biomass accumulation by modifying its association with fungal endophytes? Plants of C. quitensis from King George Island in the South Shetland archipelago (62°09' S), and Lagotellerie Island in the Antarctic Peninsula (65°53' S) were put under simulated abiotic conditions in growth chambers following predictive models of global climate change (GCC). The indirect effect of GCC on the interaction between C. quitensis and fungal endophytes was assessed in a field experiment carried out in the Antarctica, in which we eliminated endophytes under contemporary conditions and applied experimental watering to simulate increased precipitation input. We measured four proxies of plant performance. First, we found that warming (+W) significantly increased plant performance, however its effect tended to be less than watering (+W) and combined warming and watering (+T°+W). Second, the presence of fungal endophytes improved plant performance, and its effect was significantly decreased under experimental watering. Our results indicate that both biotic and abiotic factors affect ecophysiological performance, and the directions of these influences will change with climate change. Our findings provide valuable information that will help to predict future population spread and evolution through using ecological niche models under different climatic scenarios.
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Affiliation(s)
- Cristian Torres-Díaz
- Laboratorio de Genómica y Biodiversidad (LGB), Departamento de Ciencias Básicas, Universidad del Bío-Bío, Chillán, Chile
| | - Jorge Gallardo-Cerda
- Laboratorio de Genómica y Biodiversidad (LGB), Departamento de Ciencias Básicas, Universidad del Bío-Bío, Chillán, Chile
| | - Paris Lavin
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Rómulo Oses
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Fernando Carrasco-Urra
- Departamento de Botánica, Facultad de Ciencias Naturales & Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Cristian Atala
- Laboratorio de Anatomía y Ecología Funcional de Plantas (AEF), Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Ian S. Acuña-Rodríguez
- Centro de Ecología Molecular y Aplicaciones Evolutivas en Agroecosistemas (CEM), Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Peter Convey
- British Antarctic Survey, NERC, High Cross, Cambridge, United Kingdom
| | - Marco A. Molina-Montenegro
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
- Centro de Ecología Molecular y Aplicaciones Evolutivas en Agroecosistemas (CEM), Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
- Research Program "Adaptation of Agriculture to Climate Change" PIEI A2C2, Universidad de Talca, Talca, Chile
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14
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Bernareggi G, Carbognani M, Mondoni A, Petraglia A. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures. Ann Bot 2016; 118:529-39. [PMID: 27390354 PMCID: PMC4998984 DOI: 10.1093/aob/mcw125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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: 12/14/2015] [Revised: 04/24/2016] [Accepted: 05/24/2016] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. METHODS Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. KEY RESULTS A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. CONCLUSIONS Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and may play a crucial role in future plant adaptation to climate change.
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Affiliation(s)
- Giulietta Bernareggi
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Michele Carbognani
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Andrea Mondoni
- Università di Pavia, Dipartimento di Scienze della Terra e dell'Ambiente, Via S. Epifanio 14, 27100 Pavia, Italy
| | - Alessandro Petraglia
- Università di Parma, Dipartimento di Bioscienze, Parco Area delle Scienze 11/A, 43124 Parma, Italy
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15
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Rühl AT, Eckstein RL, Otte A, Donath TW. Distinct germination response of endangered and common arable weeds to reduced water potential. Plant Biol (Stuttg) 2016; 18 Suppl 1:83-90. [PMID: 25786499 DOI: 10.1111/plb.12331] [Citation(s) in RCA: 2] [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: 12/04/2014] [Accepted: 03/16/2015] [Indexed: 06/04/2023]
Abstract
Arable weeds are one of the most endangered species groups in Europe. Modern agriculture and intensive land-use management are the main causes of their dramatic decline. However, besides the changes in land use, climate change may further challenge the adaptability of arable weeds. Therefore, we investigated the response pattern of arable weeds to different water potential and temperature regimes during the phase of germination. We expected that endangered arable weeds would be more sensitive to differences in water availability and temperature than common arable weeds. To this end, we set up a climate chamber experiment where we exposed seeds of five familial pairs of common and endangered arable weed species to different temperatures (5/15, 10/20 °C) and water potentials (0.0 to -1.2 MPa). The results revealed a significant relationship between the reaction of arable weed species to water availability and their Red List status. The effects of reduced water availability on total germination, mean germination time and synchrony were significantly stronger in endangered than in common arable weeds. Therefore, global climate change may present a further threat to the survival of endangered arable weed species.
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Affiliation(s)
- A T Rühl
- Institute of Landscape Ecology and Resource Management, Justus Liebig University Giessen, Giessen, Germany
| | - R L Eckstein
- Institute of Landscape Ecology and Resource Management, Justus Liebig University Giessen, Giessen, Germany
- Department of Environmental and Life Sciences, Biology, Karlstad University, Karlstad, Sweden
| | - A Otte
- Institute of Landscape Ecology and Resource Management, Justus Liebig University Giessen, Giessen, Germany
| | - T W Donath
- Department of Landscape Ecology, Institute for Natural Resource Conservation, Christian-Albrechts-University of Kiel, Kiel, Germany
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Rolland V, Bergstrom DM, Lenné T, Bryant G, Chen H, Wolfe J, Holbrook NM, Stanton DE, Ball MC. Easy Come, Easy Go: Capillary Forces Enable Rapid Refilling of Embolized Primary Xylem Vessels. Plant Physiol 2015; 168:1636-47. [PMID: 26091819 PMCID: PMC4528742 DOI: 10.1104/pp.15.00333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/18/2015] [Indexed: 05/02/2023]
Abstract
Protoxylem plays an important role in the hydraulic function of vascular systems of both herbaceous and woody plants, but relatively little is known about the processes underlying the maintenance of protoxylem function in long-lived tissues. In this study, embolism repair was investigated in relation to xylem structure in two cushion plant species, Azorella macquariensis and Colobanthus muscoides, in which vascular water transport depends on protoxylem. Their protoxylem vessels consisted of a primary wall with helical thickenings that effectively formed a pit channel, with the primary wall being the pit channel membrane. Stem protoxylem was organized such that the pit channel membranes connected vessels with paratracheal parenchyma or other protoxylem vessels and were not exposed directly to air spaces. Embolism was experimentally induced in excised vascular tissue and detached shoots by exposing them briefly to air. When water was resupplied, embolized vessels refilled within tens of seconds (excised tissue) to a few minutes (detached shoots) with water sourced from either adjacent parenchyma or water-filled vessels. Refilling occurred in two phases: (1) water refilled xylem pit channels, simplifying bubble shape to a rod with two menisci; and (2) the bubble contracted as the resorption front advanced, dissolving air along the way. Physical properties of the protoxylem vessels (namely pit channel membrane porosity, hydrophilic walls, vessel dimensions, and helical thickenings) promoted rapid refilling of embolized conduits independent of root pressure. These results have implications for the maintenance of vascular function in both herbaceous and woody species, because protoxylem plays a major role in the hydraulic systems of leaves, elongating stems, and roots.
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Affiliation(s)
- Vivien Rolland
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Dana M Bergstrom
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Thomas Lenné
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Gary Bryant
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Hua Chen
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Joe Wolfe
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - N Michele Holbrook
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Daniel E Stanton
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology (V.R., T.L., D.E.S., M.C.B.), and Centre for Advanced Microscopy (H.C.), Australian National University, Acton, Australian Capital Territory 2601, Australia;Australian Antarctic Division, Department of Environment, Kingston, Tasmania 7050, Australia (D.M.B.);Center for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001, Australia (G.B.);School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia (J.W.); andDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 (N.M.H.)
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Weisenberger LA, Weller SG, Sakai AK. Remnants of populations provide effective source material for reintroduction of an endangered Hawaiian plant, Schiedea kaalae (Caryophyllaceae). Am J Bot 2014; 101:1954-1962. [PMID: 25366860 DOI: 10.3732/ajb.1400271] [Citation(s) in RCA: 3] [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] [Indexed: 06/04/2023]
Abstract
PREMISE OF THE STUDY Reintroductions may be essential to prevent extinction of many critically endangered species. Ideally, reintroduction efforts rely on adjacent source populations, but limited source material may necessitate crossing individuals from different and possibly distant populations. To determine the consequences of integrating multiple populations in reintroductions, we investigated levels of inbreeding depression, outbreeding depression, and heterosis for populations of Schiedea kaalae (Caryophyllaceae), an endangered species endemic to the Wai'anae and Ko'olau Mountains of O'ahu, Hawai'i. The possibility of gene flow among plants was explored through pollinator observations. METHODS Individuals from ex situ living collections of nine populations were hand-pollinated with pollen from the same plant, plants from the same population (for three populations only), or plants from different populations. Progeny were outplanted into two common gardens, one in each mountain range on O'ahu. Cumulative fitness was estimated using several independent life history stages. KEY RESULTS Inbreeding depression was minimal, and no outbreeding depression was detected. In contrast, strong heterosis was evident in progeny from between-population crosses, which had higher relative fitness than progeny from self-pollinations or within-population crosses. Observations of floral visitors provided the first evidence that biotic pollination may be important for this species. CONCLUSIONS Results demonstrate the ability to conduct genetic rescue of rare species and suggest that reintroductions may be most successful using heterotic individuals from crosses between populations and at sites where pollinators are present and promote outcrossing.
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Affiliation(s)
- Lauren A Weisenberger
- University of Hawai'i, Department of Botany, 3190 Maile Way, 408 St. John Hall, Honolulu, Hawaii 96822 USA
| | - Stephen G Weller
- University of California Irvine, Department of Ecology & Evolutionary Biology, 321 Steinhaus Hall, Irvine, California 92697 USA
| | - Ann K Sakai
- University of California Irvine, Department of Ecology & Evolutionary Biology, 321 Steinhaus Hall, Irvine, California 92697 USA
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Landesmann JB, Gundel PE, Martínez-Ghersa MA, Ghersa CM. Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis. PLoS One 2013; 8:e75820. [PMID: 24086640 PMCID: PMC3784398 DOI: 10.1371/journal.pone.0075820] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 08/17/2013] [Indexed: 12/03/2022] Open
Abstract
Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.
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Affiliation(s)
- Jennifer B. Landesmann
- Laboratorio Ecotono, INIBIOMA-CONICET, Universidad Nacional del Comahue, Bariloche, Río Negro, Argentina
- Cátedra de Ecología, Facultad de Agronomía (UBA), IFEVA-CONICET, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Pedro E. Gundel
- Cátedra de Ecología, Facultad de Agronomía (UBA), IFEVA-CONICET, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - M. Alejandra Martínez-Ghersa
- Cátedra de Ecología, Facultad de Agronomía (UBA), IFEVA-CONICET, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Claudio M. Ghersa
- Cátedra de Ecología, Facultad de Agronomía (UBA), IFEVA-CONICET, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
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Konrad W, Flues F, Schmich F, Speck T, Speck O. An analytic model of the self-sealing mechanism of the succulent plant Delosperma cooperi. J Theor Biol 2013; 336:96-109. [PMID: 23907028 DOI: 10.1016/j.jtbi.2013.07.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 06/17/2013] [Accepted: 07/16/2013] [Indexed: 11/19/2022]
Abstract
After an injury, wound-sealing in leaves of the succulent plant Delosperma cooperi takes place by deformation and movement of the entire leaf within a time span of 30-60 min. In cross sections the almost cylindrical leaves reveal a centripetal arrangement of five different tissue types. Based on anatomical data and mechanical analyses of the five hulls, representing the different tissue layers, we present an analytical model describing the self-sealing process. The inclusion of viscoelastic aspects into the models enables to predict the temporal development of the self-sealing process. The formulation of the model in terms of closed functions facilitates: (i) sensitivity studies and (ii) the transfer of the model to technical systems which are based on non-biological materials.
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Affiliation(s)
- Wilfried Konrad
- Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg i. Br., Germany; Department of Geosciences, Faculty of Science, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany.
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Sakai AK, Weller SG, Campbell DR, Culley TM, Dunbar-Wallis AK, Andres AM. Measure for measure: comparing morphological and biomass traits for sex allocation in two gynodioecious species. Am J Bot 2013; 100:1071-1082. [PMID: 23703857 DOI: 10.3732/ajb.1300045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PREMISE OF THE STUDY Sex allocation models assume male and female traits are measured in a common currency, allocation traits show heritability, and tradeoffs between investment in the two sexual functions occur. The potential for model predictions and genetic parameters to depend on the currency used is not well understood, despite frequent use of measures not in a common currency. • METHODS We analyzed the relationship between common currency (biomass of carpels, seeds, and stamens) measures and morphological measures (numbers of ovules, seeds, and pollen) in Schiedea salicaria (12-13% females) and S. adamantis (39% females), two closely related gynodioecious species. Additionally, we compared heritabilities and genetic correlations for male and female allocation between these two types of measures. • KEY RESULTS Ovule, seed, and pollen number show greater sexual dimorphism in S. adamantis than in S. salicaria. Most but not all morphological traits and analogous biomass traits are highly correlated with a linear relationship. Narrow-sense heritabilities based on the two methods are often similar, but higher for ovule number than carpel mass and lower for anther number than stamen mass in S. adamantis. Neither trait type shows negative genetic correlations between male and female function. • CONCLUSIONS Both trait types show greater sexual dimorphism in S. adamantis, and significant heritabilities suggest that morphological traits will continue to evolve with breeding system changes. Although most relationships between morphological and biomass traits are linear, curvilinear relationships for two traits suggest that caution is warranted if morphological and common currency traits are used interchangeably in fitness gain curves.
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Affiliation(s)
- Ann K Sakai
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA.
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Neuner G, Erler A, Ladinig U, Hacker J, Wagner J. Frost resistance of reproductive tissues during various stages of development in high mountain plants. Physiol Plant 2013; 147:88-100. [PMID: 22420836 DOI: 10.1111/j.1399-3054.2012.01616.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Frost resistance of reproductive vs aboveground vegetative structures was determined for six common European high alpine plant species that can be exposed to frosts throughout their whole reproductive cycle. Freezing tests were carried out in the bud, anthesis and fruit stage. Stigma and style, ovary, placenta, ovule, flower stalk/peduncle and, in Ranunculus glacialis, the receptacle were separately investigated. In all species, the vegetative organs tolerated on an average 2-5 K lower freezing temperatures than the most frost-susceptible reproductive structures that differed in their frost resistance. In almost all species, stigma, style and the flower stalk/peduncle were the most frost-susceptible reproductive structures. Initial frost damage (LT₁₀) to the most susceptible reproductive structure usually occurred between -2 and -4°C independent of the reproductive stage. The median LT₅₀ across species for stigma and style ranged between -3.4 and -3.7°C and matched the mean ice nucleation temperature (-3.7 ± 1.4°C). In R. glacialis, the flower stalk was the most frost-susceptible structure (-5.4°C), and was in contrast to the other species ice-tolerant. The ovule and the placenta were usually the most frost-resistant structures. During reproductive development, frost resistance (LT₅₀) of single reproductive structures mostly showed no significant change. However, significant increases or decreases were also observed (2.1 ± 1.2 K). Reproductive tissues of nival species generally tolerated lower temperatures than species occurring in the alpine zone. The low frost resistance of reproductive structures before, during and shortly after anthesis increases the probability of frost damage and thus, may restrict successful sexual plant reproduction with increasing altitude.
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Affiliation(s)
- Gilbert Neuner
- Unit Functional Plant Biology, Institute of Botany, University of Innsbruck, A 6020 Innsbruck, Austria.
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Meratan AA, Ghaffari SM, Niknam V, Salami M. Antioxidative responses in calli of two populations of Acanthophyllum laxiusculum with and without B-chromosomes under salt stress. Pak J Biol Sci 2013; 16:1-11. [PMID: 24199480 DOI: 10.3923/pjbs.2013.1.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Salinity is one of the most significant stresses that affect plant growth and agricultural production. Considerable efforts have therefore been made to investigate how plants respond to salt stress. To investigate the responses of Acanthophyllum to salinity stress, changes on lipid peroxidation, H2O2 content and the activity of antioxidant enzymes in calli of two Acanthophyllum laxiusculum variants, without (variant A) and with (variant B) B-chromosomes, were analyzed. Under salinity stress, lipid peroxidation and H2O2 content decreased in variant A compared to variant B. Moreover, variant A produced a higher amount of proline under salt stress than variant B. In calli of variant A, salinity stress preferentially enhanced the activities of the superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2), whereas it decreased their activity in variant B. Guaiacol peroxidase (GPX, EC 1.11.1.7) activity decreased with increasing NaCl concentrations in variant A but its activity increased in variant B. After native polyacrylamide gel electrophoresis (PAGE) analysis, calli of both A and B variants had only Mn-SOD and Fe-SOD isoforms. Expression of the isoforms mentioned above, showed marked increase in variant A; while in variant B salinity caused a significant reduction as compared to control. Moreover, changes in the CAT and GPX isoforms pattern of treated plants were in accordance with the activity changes in time. These results suggest that variant A was able to induce better antioxidative responses against salt stress than variant B.
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Affiliation(s)
- A A Meratan
- Department of Agronomy and Plant Breeding, Ramin University of Agricultural and Natural Resources, Ahwaz, Iran
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Sánchez-Vilas J, Bermúdez R, Retuerto R. Soil water content and patterns of allocation to below- and above-ground biomass in the sexes of the subdioecious plant Honckenya peploides. Ann Bot 2012; 110:839-48. [PMID: 22782243 PMCID: PMC3423814 DOI: 10.1093/aob/mcs157] [Citation(s) in RCA: 6] [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: 10/20/2011] [Accepted: 05/17/2012] [Indexed: 05/14/2023]
Abstract
BACKGROUND AND AIMS Dioecious plants often show sex-specific differences in growth and biomass allocation. These differences have been explained as a consequence of the different reproductive functions performed by the sexes. Empirical evidence strongly supports a greater reproductive investment in females. Sex differences in allocation may determine the performance of each sex in different habitats and therefore might explain the spatial segregation of the sexes described in many dimorphic plants. Here, an investigation was made of the sexual dimorphism in seasonal patterns of biomass allocation in the subdioecious perennial herb Honckenya peploides, a species that grows in embryo dunes (i.e. the youngest coastal dune formation) and displays spatial segregation of the sexes at the studied site. The water content in the soil of the male- and female-plant habitats at different times throughout the season was also examined. METHODS The seasonal patterns of soil-water availability and biomass allocation were compared in two consecutive years in male and female H. peploides plants by collecting soil and plant samples in natural populations. Vertical profiles of below-ground biomass and water content were studied by sampling soil in male- and female-plant habitats at different soil depths. KEY RESULTS The sexes of H. peploides differed in their seasonal patterns of biomass allocation to reproduction. Males invested twice as much in reproduction than females early in the season, but sexual differences became reversed as the season progressed. No differences were found in above-ground biomass between the sexes, but the allocation of biomass to below-ground structures varied differently in depth for males and females, with females usually having greater below-ground biomass than males. In addition, male and female plants of H. peploides had different water-content profiles in the soil where they were growing and, when differences existed (usually in the upper layers of the soil), the water content of the soil was higher for the female plants had than for the male plants. CONCLUSIONS Sex-differential timing of investment in reproduction and differential availability and use of resources from the soil (particularly water) are factors that probably offset the costs of reproduction in the above-ground growth in males and females of H. peploides. The results suggest that the patterns of spatial segregation of the sexes observed in H. peploides may contribute to maximize each sex's growth and reproduction.
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Affiliation(s)
- Julia Sánchez-Vilas
- Área de Ecología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
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Bascuñán-Godoy L, Sanhueza C, Cuba M, Zuñiga GE, Corcuera LJ, Bravo LA. Cold-acclimation limits low temperature induced photoinhibition by promoting a higher photochemical quantum yield and a more effective PSII restoration in darkness in the Antarctic rather than the Andean ecotype of Colobanthus quitensis Kunt Bartl (Cariophyllaceae). BMC Plant Biol 2012; 12:114. [PMID: 22827966 PMCID: PMC3490872 DOI: 10.1186/1471-2229-12-114] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [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: 01/16/2012] [Accepted: 06/27/2012] [Indexed: 05/22/2023]
Abstract
BACKGROUND Ecotypes of Colobanthus quitensis Kunt Bartl (Cariophyllaceae) from Andes Mountains and Maritime Antarctic grow under contrasting photoinhibitory conditions, reaching differential cold tolerance upon cold acclimation. Photoinhibition depends on the extent of photodamage and recovery capability. We propose that cold acclimation increases resistance to low-temperature-induced photoinhibition, limiting photodamage and promoting recovery under cold. Therefore, the Antarctic ecotype (cold hardiest) should be less photoinhibited and have better recovery from low-temperature-induced photoinhibition than the Andean ecotype. Both ecotypes were exposed to cold induced photoinhibitory treatment (PhT). Photoinhibition and recovery of photosystem II (PSII) was followed by fluorescence, CO2 exchange, and immunoblotting analyses. RESULTS The same reduction (25%) in maximum PSII efficiency (Fv/Fm) was observed in both cold-acclimated (CA) and non-acclimated (NA) plants under PhT. A full recovery was observed in CA plants of both ecotypes under dark conditions, but CA Antarctic plants recover faster than the Andean ecotype.Under PhT, CA plants maintain their quantum yield of PSII, while NA plants reduced it strongly (50% and 73% for Andean and Antarctic plants respectively). Cold acclimation induced the maintenance of PsaA and Cyt b6/f and reduced a 41% the excitation pressure in Antarctic plants, exhibiting the lowest level under PhT. xCold acclimation decreased significantly NPQs in both ecotypes, and reduced chlorophylls and D1 degradation in Andean plants under PhT.NA and CA plants were able to fully restore their normal photosynthesis, while CA Antarctic plants reached 50% higher photosynthetic rates after recovery, which was associated to electron fluxes maintenance under photoinhibitory conditions. CONCLUSIONS Cold acclimation has a greater importance on the recovery process than on limiting photodamage. Cold acclimation determined the kinetic and extent of recovery process under darkness in both C. quitensis ecotypes. The greater recovery of PSII at low temperature in the Antarctic ecotype was related with its ability to maintain PsaA, Cyt b6/f and D1 protein after photoinhibitory conditions. This is probably due to either a higher stability of these polypeptides or to the maintenance of their turnover upon cold acclimation. In both cases, it is associated to the maintenance of electron drainage from the intersystem pool, which maintains QA more oxidized and may allow the synthesis of ATP and NADPH necessaries for the regeneration of ribulose 1,5-bisphosphate in the Calvin Cycle. This could be a key factor for C. quitensis success under the harsh conditions and the short growing period in the Maritime Antarctic.
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Affiliation(s)
- Luisa Bascuñán-Godoy
- Laboratorio de Fisiología Vegetal, Centro de Estudios Avanzado Zonas Áridas, La Serena, Chile
| | - Carolina Sanhueza
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Marely Cuba
- Laboratorio de Biotecnología y Estudios Ambientales, Departamento de Ciencias y Tecnología Vegetal, Escuela de Ciencias y Tecnología, Universidad de Concepción, Campus los Ángeles, Casilla 160-C, Los Ángeles, Chile
| | - Gustavo E Zuñiga
- Laboratorio de Fisiología Vegetal, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 307 Correo 2, Santiago, Chile
| | - Luis J Corcuera
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - León A Bravo
- Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Agroindustria, Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Forestales and Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Casilla 54D, Temuco, Chile
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Bauer U, Di Giusto B, Skepper J, Grafe TU, Federle W. With a flick of the lid: a novel trapping mechanism in Nepenthes gracilis pitcher plants. PLoS One 2012; 7:e38951. [PMID: 22719998 PMCID: PMC3374759 DOI: 10.1371/journal.pone.0038951] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 05/16/2012] [Indexed: 12/04/2022] Open
Abstract
Carnivorous pitcher plants capture prey with modified leaves (pitchers), using diverse mechanisms such as ‘insect aquaplaning’ on the wet pitcher rim, slippery wax crystals on the inner pitcher wall, and viscoelastic retentive fluids. Here we describe a new trapping mechanism for Nepenthes gracilis which has evolved a unique, semi-slippery wax crystal surface on the underside of the pitcher lid and utilises the impact of rain drops to ‘flick’ insects into the trap. Depending on the experimental conditions (simulated ‘rain’, wet after ‘rain’, or dry), insects were captured mainly by the lid, the peristome, or the inner pitcher wall, respectively. The application of an anti-slip coating to the lower lid surface reduced prey capture in the field. Compared to sympatric N. rafflesiana, N. gracilis pitchers secreted more nectar under the lid and less on the peristome, thereby directing prey mainly towards the lid. The direct contribution to prey capture represents a novel function of the pitcher lid.
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Affiliation(s)
- Ulrike Bauer
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom.
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Abstract
Progamic processes are particularly temperature-sensitive and, in lowland plants, are usually drastically reduced below 10 °C and above 30 °C. Little is known about how effectively sexual processes of mountain plants function under the large temperature fluctuations at higher altitudes. The present study examines duration and thermal thresholds for progamic processes in six common plant species (Cerastium uniflorum, Gentianella germanica, Ranunculus alpestris, R. glacialis, Saxifraga bryoides, S. caesia) from different altitudinal zones in the European Alps. Whole plants were collected from natural sites shortly before anthesis and kept in a climate chamber until further processing. Flowers with receptive stigmas were hand-pollinated with allopollen and exposed to controlled temperatures between -2 and 40 °C. Pollen performance (adhesion to the stigma, germination, tube growth, fertilisation) was quantitatively analysed, using the aniline blue fluorescence method. Pollen adhesion was possible from -2 to 40 °C. Pollen germination and tube growth occurred from around 0 to 35 °C in most species. Fertilisation was observed from 5 to 30-32 °C (0-35 °C in G. germanica). The progamic phase was shortest in G. germanica (2 h at 30 °C, 12 h at 5 °C, 24 h at 0 °C), followed by R. glacialis (first fertilisation after 2 h at 30 °C, 18 h at 5 °C). In the remaining species, first fertilisation usually occurred after 4-6 h at 30 °C and after 24-30 h at 5 °C. Thus, mountain plants show remarkably flexible pollen performance over a wide temperature range and a short progamic phase, which may be essential for successful reproduction in the stochastic high-mountain climate.
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Affiliation(s)
- G Steinacher
- Faculty of Biology, Institute of Botany, University of Innsbruck, Innsbruck, Austria
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Wallace LE, Culley TM, Weller SG, Sakai AK, Kuenzi A, Roy T, Wagner WL, Nepokroeff M. Asymmetrical gene flow in a hybrid zone of Hawaiian Schiedea (Caryophyllaceae) species with contrasting mating systems. PLoS One 2011; 6:e24845. [PMID: 21949765 PMCID: PMC3176226 DOI: 10.1371/journal.pone.0024845] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 08/22/2011] [Indexed: 01/21/2023] Open
Abstract
Asymmetrical gene flow, which has frequently been documented in naturally occurring hybrid zones, can result from various genetic and demographic factors. Understanding these factors is important for determining the ecological conditions that permitted hybridization and the evolutionary potential inherent in hybrids. Here, we characterized morphological, nuclear, and chloroplast variation in a putative hybrid zone between Schiedea menziesii and S. salicaria, endemic Hawaiian species with contrasting breeding systems. Schiedea menziesii is hermaphroditic with moderate selfing; S. salicaria is gynodioecious and wind-pollinated, with partially selfing hermaphrodites and largely outcrossed females. We tested three hypotheses: 1) putative hybrids were derived from natural crosses between S. menziesii and S. salicaria, 2) gene flow via pollen is unidirectional from S. salicaria to S. menziesii and 3) in the hybrid zone, traits associated with wind pollination would be favored as a result of pollen-swamping by S. salicaria. Schiedea menziesii and S. salicaria have distinct morphologies and chloroplast genomes but are less differentiated at the nuclear loci. Hybrids are most similar to S. menziesii at chloroplast loci, exhibit nuclear allele frequencies in common with both parental species, and resemble S. salicaria in pollen production and pollen size, traits important to wind pollination. Additionally, unlike S. menziesii, the hybrid zone contains many females, suggesting that the nuclear gene responsible for male sterility in S. salicaria has been transferred to hybrid plants. Continued selection of nuclear genes in the hybrid zone may result in a population that resembles S. salicaria, but retains chloroplast lineage(s) of S. menziesii.
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Affiliation(s)
- Lisa E Wallace
- Department of Biological Sciences, Mississippi State University, Mississippi State, Mississippi, United States of America.
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Yang J, Wang DQ, Yao Y, Jin XF. [Observation on biological characteristics of wild Pseudostellaria heterophylla]. Zhong Yao Cai 2011; 34:1323-1328. [PMID: 22259994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To study the status and regular pattern in growing development of wild Pseudostellaria heterophylla. METHODS Observed and studied on wild Pseudostellaria heterophylla during growth periods continuously. RESULTS The growing development of Pseudostellaria heterophylla could be divided into three stages: asexual reproduction stage, coexistence of asexual and sexual reproduction stage. In the first two years of seed germination, there was only asexual reproduction, from which substitute tuberous root and cauline tuberous root were formed; Afterward flowering and fructifying sexual reproduction occurred to the plant that had developed from tuberous root while it continued with asexual reproduction; Only sexual reproduction existed during the last year of the Pseudostellaria heterophylla plant before its death. The Pseudostellaria heterophylla plant above ground grew from early spring to late autumn and over-wintered with tuberous root. There were two patterns of asexual reproduction: substitution with tuberous root in spring and expanding of adventitious root on stolon into cauline tuberous root in autumn. All tuberous roots of Pseudostellaria heterophylla were originated from adventitious root; The existence of tuberous root was one year at most; The rapidly expanding period of tuberous root was during February and March. CONCLUSIONS The results provide a reference for reformative cultivation of Pseudostellaria heterophylla.
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Affiliation(s)
- Jun Yang
- Anhui Key Laboratory of Modernized Chinese Material Medica, Department of Pharmacy, Anhui University of Traditional Chinese Medicine, Hefei 230031, China.
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Hori Y, Nishidate K, Nishiyama M, Kanahama K, Kanayama Y. Flowering and expression of flowering-related genes under long-day conditions with light-emitting diodes. Planta 2011; 234:321-30. [PMID: 21431295 DOI: 10.1007/s00425-011-1397-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 02/28/2011] [Indexed: 05/25/2023]
Abstract
The effects of light quality on flowering time were investigated in Gypsophila paniculata, which is a long-day cut flower, and with Arabidopsis under long-day conditions with light-emitting diodes (LEDs). Gypsophila paniculata plants were grown under natural daylight and flowering was controlled by long-day treatment with a weak LED light of a single color in the night. Flowering was promoted not by blue light, but by far-red light in G. paniculata, while flowering was promoted by both light colors in Arabidopsis. FT homologs of G. paniculata GpFT1 and GpFT2 were differentially expressed under long-day conditions with white light, suggesting that they play roles in flowering at different stages of reproductive development. GpFTs and FT gene expression was not induced by far-red light in G. paniculata or Arabidopsis. Instead, the expression of the SOC1 homolog of G. paniculata GpSOC1 and SOC1 was induced by far-red light in G. paniculata and Arabidopsis. Flowering was promoted by induction of FT and SOC1 expression with blue light in Arabidopsis, whereas GpFTs and GpSOC1 expression was low with blue light induction in G. paniculata. The relationship between flowering and the expression of FT and SOC1 in Arabidopsis was confirmed with ft and soc1 mutants. These results suggest that long-day conditions with far-red light promote flowering through SOC1 and its homologs, while the conditions with blue light do not promote flowering in G. paniculata, because of low expression of GpFTs and GpSOC1 in contrast to that in Arabidopsis.
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Affiliation(s)
- Yoshimi Hori
- Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan
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Bonhomme V, Pelloux-Prayer H, Jousselin E, Forterre Y, Labat JJ, Gaume L. Slippery or sticky? Functional diversity in the trapping strategy of Nepenthes carnivorous plants. New Phytol 2011; 191:545-554. [PMID: 21434933 DOI: 10.1111/j.1469-8137.2011.03696.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The pitcher-shaped leaves of Nepenthes carnivorous plants have been considered as pitfall traps that essentially rely on slippery surfaces to capture insects. But a recent study of Nepenthes rafflesiana has shown that the viscoelasticity of the digestive fluid inside the pitchers plays a key role. Here, we investigated whether Nepenthes species exhibit diverse trapping strategies. We measured the amount of slippery wax on the pitcher walls of 23 taxa and the viscoelasticity of their digestive liquid and compared their retention efficiency on ants and flies. The amount of wax was shown to vary greatly between species. Most mountain species exhibited viscoelastic digestive fluids while water-like fluids were predominant in lowland species. Both characteristics contributed to insect trapping but wax was more efficient at trapping ants while viscoelasticity was key in trapping insects and was even more efficient than wax on flies. Trap waxiness and fluid viscoelasticity were inversely related, suggesting the possibility of an investment trade-off for the plants. Therefore Nepenthes pitcher plants do not solely employ slippery devices to trap insects but often employ a viscoelastic strategy. The entomofauna specific to the plant's habitat may exert selective pressures, favouring one trapping strategy at the expense of the other.
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Affiliation(s)
- Vincent Bonhomme
- Université Montpellier II, CNRS, UMR AMAP: botAnique et bioinforMatique de l'Architecture des Plantes, CIRAD - TA A51/PS2 Boulevard de la Lironde, F-34398 Montpellier cedex 5, France
| | - Hervé Pelloux-Prayer
- Université Montpellier II, CNRS, UMR AMAP: botAnique et bioinforMatique de l'Architecture des Plantes, CIRAD - TA A51/PS2 Boulevard de la Lironde, F-34398 Montpellier cedex 5, France
| | - Emmanuelle Jousselin
- INRA, UMR CBGP, Campus International de Baillarguet, CS 30016, 34988 Montferrier-sur-Lez, France
| | - Yoël Forterre
- CNRS, Université de Provence IUSTI, Technopole Château-Gombert, 13000 Marseille, France
| | - Jean-Jacques Labat
- Pépinière Nature et Paysages et Jardin Botanique de Plantes Carnivores, Peyrusse-Massas, France
| | - Laurence Gaume
- Université Montpellier II, CNRS, UMR AMAP: botAnique et bioinforMatique de l'Architecture des Plantes, CIRAD - TA A51/PS2 Boulevard de la Lironde, F-34398 Montpellier cedex 5, France
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Adlassnig W, Peroutka M, Lendl T. Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities. Ann Bot 2011; 107:181-94. [PMID: 21159782 PMCID: PMC3025736 DOI: 10.1093/aob/mcq238] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Carnivorous pitcher plants (CPPs) use cone-shaped leaves to trap animals for nutrient supply but are not able to kill all intruders of their traps. Numerous species, ranging from bacteria to vertrebrates, survive and propagate in the otherwise deadly traps. This paper reviews the literature on phytotelmata of CPPs. PITCHER Fluid as a Habitat The volumes of pitchers range from 0·2 mL to 1·5 L. In Nepenthes and Cephalotus, the fluid is secreted by the trap; the other genera collect rain water. The fluid is usually acidic, rich in O(2) and contains digestive enzymes. In some taxa, toxins or detergents are found, or the fluid is extremely viscous. In Heliamphora or Sarracenia, the fluid differs little from pure water. INQUILINE Diversity Pitcher inquilines comprise bacteria, protozoa, algae, fungi, rotifers, crustaceans, arachnids, insects and amphibia. The dominant groups are protists and Dipteran larvae. The various species of CPPs host different sets of inquilines. Sarracenia purpurea hosts up to 165 species of inquilines, followed by Nepenthes ampullaria with 59 species, compared with only three species from Brocchinia reducta. Reasons for these differences include size, the life span of the pitcher as well as its fluid. MUTUALISTIC: Activities Inquilines closely interact with their host. Some live as parasites, but the vast majority are mutualists. Beneficial activities include secretion of enzymes, feeding on the plant's prey and successive excretion of inorganic nutrients, mechanical break up of the prey, removal of excessive prey and assimilation of atmospheric N(2). CONCLUSIONS There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization.
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Affiliation(s)
- Wolfram Adlassnig
- University of Vienna, Cell Imaging and Ultrastructure Research Unit, Althanstrasse 14, A-1090 Vienna, Austria.
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Westergaard KB, Alsos IG, Popp M, Engelskjøn T, Flatberg KI, Brochmann C. Glacial survival may matter after all: nunatak signatures in the rare European populations of two west-arctic species. Mol Ecol 2010; 20:376-93. [PMID: 21156004 DOI: 10.1111/j.1365-294x.2010.04928.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stiles AR, Bautista D, Atalay E, Babaoğlu M, Terry N. Mechanisms of boron tolerance and accumulation in plants: a physiological comparison of the extremely boron-tolerant plant species, Puccinellia distans, with the moderately boron-tolerant Gypsophila arrostil. Environ Sci Technol 2010; 44:7089-7095. [PMID: 20738130 DOI: 10.1021/es1016334] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The physiological characteristics of the extremely boron (B)-tolerant plant species, Puccinellia distans, were compared with those of the moderately tolerant Gypsophila arrostil, two species collected from a B-mining area of Eskişehir, Turkey. Boron was supplied to plants hydroponically at B concentrations ranging from 0.5 to 50 mg B/L for G. arrostil, and from 0.5 to 2000 mg B/L for P. distans. The results show that P. distans has a strikingly greater tolerance to B than G. arrostil. While G. arrostil was unable to survive B supply concentrations greater than 50 mg B/L, P. distans grew at B supply concentrations exceeding 1250 mg B/L. Our research supports the conclusion that from 0.5 to 50 mg B/L, P. distans is better able to restrict the accumulation of B in the whole plant, and the transport of B from root to shoot, than G. arrostil. We propose that P. distans uses several strategies to achieve B tolerance including the ability to restrict the accumulation of B relative to its accumulation of biomass, the ability to restrict the transport of B from root to shoot, and, to a lesser extent, the ability to tolerate high concentrations of B in its shoot and root tissues.
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Affiliation(s)
- Amanda R Stiles
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, USA
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Bauer U, Willmes C, Federle W. Effect of pitcher age on trapping efficiency and natural prey capture in carnivorous Nepenthes rafflesiana plants. Ann Bot 2009; 103:1219-26. [PMID: 19307189 PMCID: PMC2685315 DOI: 10.1093/aob/mcp065] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [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: 12/14/2008] [Revised: 01/15/2009] [Accepted: 02/10/2009] [Indexed: 05/04/2023]
Abstract
BACKGROUND AND AIMS Nepenthes pitchers are sophisticated traps that employ a variety of mechanisms to attract, capture and retain prey. The underlying morphological structures and physiological processes are subject to change over the lifetime of a pitcher. Here an investigation was carried out on how pitcher properties and capture efficiency change over the first 2 weeks after pitcher opening. METHODS Prey capture, trapping efficiency, extrafloral nectar secretion, pitcher odour, as well as pH and viscoelasticity of the digestive fluid in N. rafflesiana pitchers were monitored in the natural habitat from pitcher opening up to an age of 2 weeks. KEY RESULTS Pitchers not only increased their attractiveness over this period by becoming more fragrant and secreting more nectar, but also gained mechanical trapping efficiency via an enhanced wettability of the upper pitcher rim (peristome). Consistently, natural prey capture was initially low and increased 3-6 d after opening. It was, however, highly variable within and among pitchers. At the same time, the pH and viscoelasticity of the digestive fluid decreased, suggesting that the latter is not essential for effective prey capture. CONCLUSIONS Prey capture and attraction by Nepenthes are dynamic processes strongly influenced by the changing properties of the pitcher. The results confirm insect aquaplaning on the peristome as the main capture mechanism in N. rafflesiana.
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Affiliation(s)
- Ulrike Bauer
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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Sánchez-Vilas J, Retuerto R. Sex-specific physiological, allocation and growth responses to water availability in the subdioecious plant Honckenya peploides. Plant Biol (Stuttg) 2009; 11:243-254. [PMID: 19228331 DOI: 10.1111/j.1438-8677.2008.00105.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The gender of dimorphic plant species is often affected by ecophysiological variables. Differences have been interpreted as a response of the sexes to meet specific resource demands associated with reproduction. This study investigated whether sex-specific variations in ecophysiological traits in response to water availability determine the performance of each sex in different habitats, and therefore promote extreme spatial segregation of the sexes in the subdioecious plant, Honckenya peploides. Twenty-seven plants of each sex were individually potted in dune sand and assigned randomly to one of three water treatments. Well-watered plants were watered daily to field capacity, whereas plants in the moderate and high-water stress treatments received 40% and 20%, respectively, of the water given to well-watered plants. Photochemical efficiency, leaf spectral properties and components of relative growth rate (leaf area ratio and net assimilation rate) were measured. Photochemical efficiencies integrated over time were higher in male than in female plants. Water deficit decreased maximum quantum yield in female plants more rapidly than in male plants, but female plants (unlike male plants) had recovered to initial values by the end of the experiment. Maximum quantum yield in male plants was more affected by water stress than in female plants, indicating that male plants were more susceptible to photoinhibition. The two sexes did not differ in growth rate, but male plants invested a higher proportion of their biomass in leaves, had a higher leaf area per unit biomass and lower net assimilation rate relative to female plants. Female plants had a higher water content and succulence than male plants. Differences in stomatal density between the sexes depended on water availability. The results suggest that the two sexes of H. peploides have different strategies for coping with water stress. The study also provides evidence of sex differences in allocation traits. We conclude that between-sex differences in ecophysiological and allocation traits may contribute to explain habitat-related between-sex differences in performance and, therefore, the spatial segregation of the sexes.
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Affiliation(s)
- J Sánchez-Vilas
- Department of Ecology, Faculty of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain
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Schaefer HM, Ruxton GD. Fatal attraction: carnivorous plants roll out the red carpet to lure insects. Biol Lett 2008; 4:153-5. [PMID: 18198137 PMCID: PMC2429934 DOI: 10.1098/rsbl.2007.0607] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 12/28/2007] [Accepted: 01/02/2008] [Indexed: 11/12/2022] Open
Abstract
We provide the first experimental test of the hypothesis that the coloration of carnivorous plants can act as a signal to lure insects and thus enhance capture rates. An experimental approach was needed to separate effects of the visual appearance of plants from those of traits that may correlate with appearance and also affect capture rates. We compared insect capture rates of pitcher plants with artificially coloured red and green pitchers in a paired design, and found that plants with red pitchers captured significantly more flying insects. Thus, we present the first experimental evidence of visual signalling in carnivorous plants. Further, it has previously been suggested that carnivorous plants use contrasting stripes or UV marks on their pitchers to lure insects; our results emphasize that insect traps do not need to sport contrasting colours to be attractive; it might be sufficient to be different from the background.
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Affiliation(s)
- H Martin Schaefer
- Faculty of Biology, Department of Evolutionary Biology and Animal Ecology, University of Freiburg, Hauptstrasse 1, 79104 Freiburg, Germany.
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Ducousso M, Ramanankierana H, Duponnois R, Rabévohitra R, Randrihasipara L, Vincelette M, Dreyfus B, Prin Y. Mycorrhizal status of native trees and shrubs from eastern Madagascar littoral forests with special emphasis on one new ectomycorrhizal endemic family, the Asteropeiaceae. New Phytol 2008; 178:233-238. [PMID: 18371004 DOI: 10.1111/j.1469-8137.2008.02389.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Marc Ducousso
- Laboratoire des Symbioses Tropicales et Méditerranéennes, CIRAD, UMR LSTM, Montpellier F-34398, France
- Author for correspondence: tel +33(0)4 67 59 37 63; fax +33(0)4 67 59 38 02; email )
| | - Heriniaina Ramanankierana
- Laboratoire de Microbiologie de l'Environnement/Centre National de Recherche sur l'Environnement, Antananarivo 101, Madagascar
| | | | - Raymond Rabévohitra
- FOFIFA (National Centre of Applied Research in Rural Development), BP 745, Antananarivo 101, Madagascar
| | | | - Manon Vincelette
- QIT Madagascar Minerals S.A., B.P. 4003, Antananarivo 101, Madagascar (
| | | | - Yves Prin
- Laboratoire des Symbioses Tropicales et Méditerranéennes, CIRAD, UMR LSTM, Montpellier F-34398, France
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Abstract
BACKGROUND The carnivorous plants of the genus Nepenthes, widely distributed in the Asian tropics, rely mostly on nutrients derived from arthropods trapped in their pitcher-shaped leaves and digested by their enzymatic fluid. The genus exhibits a great diversity of prey and pitcher forms and its mechanism of trapping has long intrigued scientists. The slippery inner surfaces of the pitchers, which can be waxy or highly wettable, have so far been considered as the key trapping devices. However, the occurrence of species lacking such epidermal specializations but still effective at trapping insects suggests the possible implication of other mechanisms. METHODOLOGY/PRINCIPAL FINDINGS Using a combination of insect bioassays, high-speed video and rheological measurements, we show that the digestive fluid of Nepenthes rafflesiana is highly viscoelastic and that this physical property is crucial for the retention of insects in its traps. Trapping efficiency is shown to remain strong even when the fluid is highly diluted by water, as long as the elastic relaxation time of the fluid is higher than the typical time scale of insect movements. CONCLUSIONS/SIGNIFICANCE This finding challenges the common classification of Nepenthes pitchers as simple passive traps and is of great adaptive significance for these tropical plants, which are often submitted to high rainfalls and variations in fluid concentration. The viscoelastic trap constitutes a cryptic but potentially widespread adaptation of Nepenthes species and could be a homologous trait shared through common ancestry with the sundew (Drosera) flypaper plants. Such large production of a highly viscoelastic biopolymer fluid in permanent pools is nevertheless unique in the plant kingdom and suggests novel applications for pest control.
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Affiliation(s)
| | - Yoel Forterre
- IUSTI CNRS UMR 6595, Université de Provence, Technopole Château-Gombert, Marseille, France
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Bravo LA, Saavedra-Mella FA, Vera F, Guerra A, Cavieres LA, Ivanov AG, Huner NPA, Corcuera LJ. Effect of cold acclimation on the photosynthetic performance of two ecotypes of Colobanthus quitensis (Kunth) Bartl. J Exp Bot 2007; 58:3581-90. [PMID: 18057038 DOI: 10.1093/jxb/erm206] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The effects of cold acclimation of two ecotypes (Antarctic and Andes) of Colobanthus quitensis (Kunth) Bartl. Caryophyllaceae on their photosynthetic characteristics and performance under high light (HL) were compared. Non-acclimated plants of the Antarctic ecotype exhibited a higher (34%) maximal rate of photosynthesis than the Andes ecotype. In cold-acclimated plants the light compensation point was increased. Dark respiration was significantly increased during the exposure to 4 degrees C in both ecotypes. Cold-acclimated Antarctic plants showed higher Phi(PSII) and qP compared with the Andes ecotype. In addition, the Antarctic ecotype exhibited higher heat dissipation (NPQ), especially in the cold-acclimated state, which was mainly associated with the fast relaxing component of non-photochemical quenching (NPQ(F)). By contrast, the Andes ecotype exhibited a lower NPQ(F) and a significant increase in the slowly relaxing component (NPQ(s)) at low temperature and HL, indicating higher sensitivity to low temperature-induced photoinhibition. Although the xanthophyll cycle was fully operational in both ecotypes, cold-acclimated Antarctic plants exposed to HL exhibited higher epoxidation state of the xanthophyll cycle pigments (EPS) compared with the cold-acclimated Andes ecotype. Thus, the photosynthetic apparatus of the Antarctic ecotype operates more efficiently than that of the Andes one, under a combination of low temperature and HL. The ecotype differences are discussed in relation to the different climatic conditions of the two Colobanthus.
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Affiliation(s)
- León A Bravo
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Correo 3, Concepción, Chile.
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Abstract
BACKGROUND "Explosive" adaptive radiations on islands remain one of the most puzzling evolutionary phenomena. The rate of phenotypic and ecological adaptations is extremely fast during such events, suggesting that many genes may be under fairly strong selection. However, no evidence for adaptation at the level of protein coding genes was found, so it has been suggested that selection may work mainly on regulatory elements. Here we report the first evidence that positive selection does operate at the level of protein coding genes during rapid adaptive radiations. We studied molecular adaptation in Hawaiian endemic plant genus Schiedea (Caryophyllaceae), which includes closely related species with a striking range of morphological and ecological forms, varying from rainforest vines to woody shrubs growing in desert-like conditions on cliffs. Given the remarkable difference in photosynthetic performance between Schiedea species from different habitats, we focused on the "photosynthetic" Rubisco enzyme, the efficiency of which is known to be a limiting step in plant photosynthesis. RESULTS We demonstrate that the chloroplast rbcL gene, encoding the large subunit of Rubisco enzyme, evolved under strong positive selection in Schiedea. Adaptive amino acid changes occurred in functionally important regions of Rubisco that interact with Rubisco activase, a chaperone which promotes and maintains the catalytic activity of Rubisco. Interestingly, positive selection acting on the rbcL might have caused favorable cytotypes to spread across several Schiedea species. SIGNIFICANCE We report the first evidence for adaptive changes at the DNA and protein sequence level that may have been associated with the evolution of photosynthetic performance and colonization of new habitats during a recent adaptive radiation in an island plant genus. This illustrates how small changes at the molecular level may change ecological species performance and helps us to understand the molecular bases of extremely fast rate of adaptation during island adaptive radiations.
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Weller SG, Sakai AK, Culley TM, Campbell DR, Dunbar-Wallis AK. Predicting the pathway to wind pollination: heritabilities and genetic correlations of inflorescence traits associated with wind pollination in Schiedea salicaria (Caryophyllaceae). J Evol Biol 2006; 19:331-42. [PMID: 16599909 DOI: 10.1111/j.1420-9101.2005.01038.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The transition from biotic to abiotic pollination was investigated using Schiedea, a genus exhibiting a remarkable diversity of inflorescence architecture associated with pollination biology. Heritabilities and genetic correlations of inflorescence traits were estimated in gynodioecious Schiedea salicaria (Caryophyllaceae), a species that has likely undergone a recent transition to wind-pollination. Using a partial diallel crossing design, significant narrow-sense heritabilities were detected for inflorescence condensation (h2 = 0.56 to 0.68 in the two sexes) and other traits related to the extent of wind pollination in Schiedea species. Heritabilities were generally higher in hermaphrodites than in females. Strong genetic correlations may constrain the evolution of some inflorescence traits that facilitate wind pollination, such as simultaneous shortening of inflorescence length and elongation of the subtending internode. The presence of significant narrow-sense heritabilities for traits associated with wind pollination suggests, however, that selection for more effective wind pollination in the windy, pollinator-limited environments where S. salicaria grows could lead to the evolution of the highly condensed inflorescences characteristic of other wind-pollinated species of Schiedea.
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Affiliation(s)
- S G Weller
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA.
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Culley TM, Dunbar-Wallis AK, Sakai AK, Weller SG, Mishio M, Campbell DR, Herzenach M. Genetic variation of ecophysiological traits in two gynodioecious species of Schiedea (Caryophyllaceae). New Phytol 2006; 169:589-601. [PMID: 16411961 DOI: 10.1111/j.1469-8137.2005.01588.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Evolution of dimorphic breeding systems may involve changes in ecophysiological traits as well as floral morphology because of greater resource demands on females. Differences between related species suggest that ecophysiological traits should be heritable, and species with higher female frequencies should show greater sexual differentiation. We used modified partial diallel crossing designs to estimate narrow-sense heritabilities and genetic correlations of sex-specific ecophysiological and morphological traits in closely related gynodioecious Schiedea salicaria (13% females) and Schiedea adamantis (39% females). In S. salicaria, hermaphrodites and females differed in photosynthetic rate and specific leaf area (SLA). Narrow-sense heritabilities were significant for stomatal conductance, SLA and inflorescence number in hermaphrodites, and for SLA and inflorescence number in females. Schiedea adamantis had no sexual dimorphism in measured traits; stomatal conductance, stem number and inflorescence number were heritable in females, and stem number was heritable in hermaphrodites. In both species, significant genetic correlations of traits between sexes were rare, indicating that traits can evolve independently in response to sex-differential selection. Significant genetic correlations were detected between certain traits within sexes of both species. Low heritability of some ecophysiological traits may reflect low additive genetic variability or high phenotypic plasticity in these traits.
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Affiliation(s)
- Theresa M Culley
- Department of Ecology and Evolutionary Biology, University of California Irvine 92697, USA.
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Kephart S, Reynolds RJ, Rutter MT, Fenster CB, Dudash MR. Pollination and seed predation by moths on Silene and allied Caryophyllaceae: evaluating a model system to study the evolution of mutualisms. New Phytol 2006; 169:667-80. [PMID: 16441748 DOI: 10.1111/j.1469-8137.2005.01619.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nursery pollinators, and the plants they use as hosts for offspring development, function as exemplary models of coevolutionary mutualism. The two pre-eminent examples--fig wasps and yucca moths--show little variation in the interaction: the primary pollinator is an obligate mutualist. By contrast, nursery pollination of certain Caryophyllaceae, including Silene spp., by two nocturnal moth genera, Hadena and Perizoma, ranges from antagonistic to potentially mutualistic, offering an opportunity to test hypotheses about the factors that promote or discourage the evolution of mutualism. Here, we review nursery pollination and host-plant interactions in over 30 caryophyllaceous plants, based on published studies and a survey of researchers investigating pollination, seed predation, and moth morphology and behavior. We detected little direct evidence of mutualism in these moth-plant interactions, but found traits and patterns in both that are nonetheless consistent with the evolution of mutualism and merit further attention.
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Affiliation(s)
- Susan Kephart
- Department of Biology, Willamette University, Salem, OR 97301, USA.
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Affiliation(s)
- Susan Kephart
- Department of Biology, Willamette University, Salem, OR 97301, USA.
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45
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Abstract
Abstract Levels of selfing and resource allocation patterns were investigated in Schiedea salicaria (Caryophyllaceae), a gynodioecious species with high levels of inbreeding depression and nuclear control of male sterility. Selfing levels were higher in hermaphrodites than females, especially when adjusted for early acting inbreeding depression. The sexes of S. salicaria were similar in most allocation patterns including number of flowers and capsules per inflorescence, seeds per flower, and seed mass. Seeds produced by females had higher levels of germination than seeds of hermaphrodites, a likely result of high selfing levels and the expression of inbreeding depression in the progeny of hermaphrodites. Invasion of females in populations of S. salicaria is probably related to the expression of inbreeding depression at germination and in later life history stages. Comparisons with related species of Schiedea that also have nuclear control of male sterility suggest that reallocation of resources in hermaphrodites to male function occurs as females increase in frequency, but that resource reallocation is not important for the success of females when they first invade populations.
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Affiliation(s)
- S G Weller
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92967, USA.
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Abstract
Deschampsia antarctica and Colobanthus quitensis are the only vascular plants to have colonized the Maritime Antarctic, which is characterized by its permanently low temperature and frequent summer frosts. To understand how the plants survive freezing temperatures year-round, antifreeze activity was assayed in apoplastic extracts obtained from both non-acclimated and cold-acclimated Antarctic plants. By observing the shape of ice crystals grown in dilution series of the extracts, it was found that D. antarctica had antifreeze activity, but C. quitensis did not. D. antarctica exhibited antifreeze activity in the non-acclimated state and this activity increased after cold acclimation. The antifreeze activity in D. antarctica was labile to proteolysis and high temperature, active over a wide pH range, and associated with molecules greater than 10 kDa in molecular weight. These results show that D. antarctica produces antifreeze proteins that are secreted into the apoplast. When examined by SDS-PAGE, the apoplastic extracts from cold-acclimated D. antarctica exhibited 13 polypeptides. It is concluded that D. antarctica accumulates AFPs as part of its mechanism of freezing tolerance. Moreover, this is the first plant in which antifreeze activity has been observed to be constitutive.
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Affiliation(s)
- León A Bravo
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
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Carter CT, Ungar IA. Relationships between seed germinability of Spergularia marina (Caryophyllaceae) and the formation of zonal communities in an inland salt marsh. Ann Bot 2004; 93:119-125. [PMID: 14672911 PMCID: PMC4241073 DOI: 10.1093/aob/mch018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS The formation of zonal communities may be attributed to differences in germination across the community and to timing of germination of seeds present in the seed bank. Our goals were two-fold: (1) to assess the annual germination pattern of Spergularia marina; and (2) to determine whether germination of S. marina differed across zonal communities. METHODS Fresh seeds were buried in an experimental garden in polyester bags. Bags were harvested monthly for 1 year and exposed to differing 12 h/12 h temperature regimes (5/15 degrees C, 5/25 degrees C, 15/25 degrees C and 20/35 degrees C) with a 12 h dark/12 h light photoperiod. Replicate seeds were exposed to 24 h dark. Seeds were also placed in different zonal communities to assess germinability in the field. KEY RESULTS Spergularia marina has a primary physiological dormancy. Conditional dormancy occurs from December to May and non-dormancy from June to November. Field germination initiates in the spring when temperatures are cool and salinity is low due to flooding, and ceases in the summer when temperatures exceed germination requirements. Spergularia marina has a light requirement for germination. CONCLUSIONS If seeds become buried in the field or are light inhibited by Phragmites australis, they will remain dormant until they receive an adequate amount of light for germination. Since S. marina can germinate across all zones in a salt-marsh community, the formation of zonal communities is not determined at the germination stage, but at some later stage of development.
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Affiliation(s)
- Christy T Carter
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, USA.
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Mazer SJ, Lowry DE, Hansen T. Effects of nutrient availability on primary sexual traits and their response to selection in Spergularia marina (Caryophyllaceae). J Evol Biol 2003; 16:767-78. [PMID: 14632239 DOI: 10.1046/j.1420-9101.2003.00555.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- S J Mazer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
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Delesalle VA, Mazer SJ. The neighborhood matters: effects of neighbor number and sibling (or kin) competition on floral traits in Spergularia marina (Caryophyllaceae). Evolution 2002; 56:2406-13. [PMID: 12583581 DOI: 10.1111/j.0014-3820.2002.tb00166.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Effects of abiotic factors on the expression of floral and gender traits have been well documented in wild plant species; by contrast, little is known of the effect(s) on an individual's floral phenotype of the genetic composition of its neighboring conspecifics. Here we report the results of a greenhouse experiment conducted to detect the effects of genetic attributes of an individual's local environment on the expression of floral traits in the selfing annual, Spergularia marina (Caryophyllaceae). First, to test the hypothesis that negative effects of intraspecific competition are stronger when an individual competes with genetically similar individuals than when it competes with unrelated genotypes, we evaluated the effects of the number of nearest-neighbor kin (vs. unrelated individuals) on floral traits. Plants adjacent to two kin produced significantly fewer stamens per flower than plants adjacent to one or no siblings, indicating that kin competition reduced allocation to male function. Second, to test the hypothesis that the genetic diversity of a neighborhood influences the phenotype of a focal plant, we determined whether the number of maternal families represented among an individual's nearest neighbors influences its phenotype. The number of maternal families surrounding a focal plant did not affect floral trait expression. These results suggest that in S. marina, male function is more sensitive than female function to the genetic environment and that as an individual's genetic similarity to its neighbors increases, so do the negative effects of competition for limited resources.
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An CI, Takekawa S, Okazawa A, Fukusaki EI, Kobayashi A. Degradation of a peptide in pitcher fluid of the carnivorous plant Nepenthes alata Blanco. Planta 2002; 215:472-477. [PMID: 12111230 DOI: 10.1007/s00425-002-0768-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2001] [Accepted: 10/06/2001] [Indexed: 05/23/2023]
Abstract
Carnivorous plants acquire substantial amounts of nitrogen from insects. The tropical carnivorous plant Nepenthes produces trapping organs called pitchers at the tips of tendrils elongated from leaf ends. Acidic fluid is secreted at the bottoms of the pitchers. The pitcher fluid includes several hydrolytic enzymes, and some, such as aspartic proteinase, are thought to be involved in nitrogen acquisition from insect proteins. To understand the nitrogen-acquisition process, it is essential to identify the protein-degradation products in the pitcher fluid. To gain insight into protein degradation in pitcher fluid, we used the oxidized B-chain of bovine insulin as a model substrate, and its degradation by the pitcher fluid of N. alata was investigated using liquid chromatography-mass spectrometry (LC-MS). LC-MS analysis of the degradation products revealed that the oxidized B-chain of bovine insulin was initially cleaved at aromatic amino acids such as phenylalanine and tyrosine. These cleavage sites are similar to those of aspartic proteinases from other plants and animals. The presence of a series of peptide fragments as degradation products suggests that exopeptidase(s) is also present in the pitcher fluid. Amino acid analysis and peptide fragment analysis of the degradation products demonstrated that three amino acids plus small peptides were released from the oxidized B-chain of bovine insulin, suggesting that insect proteins are readily degraded to small peptides and amino acids in the pitcher fluid of N. alata.
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Affiliation(s)
- Chung-Il An
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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