Many Parasitic Plants
dePamphilis, Claude D. ,
Wafula, Eric , Zhang, Yeting , Der, Joshua , Mirarab, Siavash
, Ayyampalayam, Raj , Villegente, Matthieu , Wulff, Adrien
, Fogliani, Bruno , Gateble, Gildas , Munzinger, Jerome ,
Westwood, Jim , Warnow, Tandy , Wong, Gane Ka-Shu ,
Leebens-Mack, James H. .
Parasitic and mycotrophic plants as foci for horizontal gene transfer: evidence from 1kp transcriptome data.
Parasitic and mycotrophic plants have intimate structural connections with host plants and/or mycorrhizal fungi. Along with their often extreme adaptations to a heterotrophic lifestyle, their close biotic associations provide opportunities for horizontal gene transfer (HGT). The 1KP database includes transcriptome data from taxa representing at least 7 independent origins of parasitism and two mycoheterotrophic lineages: Orobanchaceae, Lennoaceae, Apodanthaceae, Santalales (Olacaceae, Viscaceae, Loranthaceae, Santalaceae, and Balanophoraceae) Krameriaceae, Cuscuta, Cassytha, Ericaceae and Parasitaxus. We are applying blast-based and phylogenetic approaches to identify both candidate and high confidence transcribed HGT sequences from 1kp transcriptome datasets. With analyses still ongoing, the results to date suggest that there have been many HGT events from host-plant lineages to parasitic lineages. Many examples that look at first analysis like HGT are likely due to other factors stemming from host contamination, mobile RNA transfer from living hosts, and a variety of potential artifacts, including extreme rate heterogeneity in some lineages. Although parasitic plants may be special focal points for HGT events in plants, functionally significant HGTs are not restricted to parasite lineages. High confidence assessment of HGT events from 1kp transcriptome datasets is challenging, but helps to reveal an underappreciated but important source of genetic variation in plants.
1 - Pennsylvania State University, Department Of Biology, 101 Life Sciences Building, University Park, PA, 16802, USA
2 - Penn State University, Biology, University Park, PA, USA
3 - California State University, Fullerton, Biology, Fullerton, CA, USA
4 - University of Texas, Computer Science, Austin, TX, USA
5 - University of Georgia , Plant Biology, Athens, GA, USA
6 - Agronomique néo-Calédonien (IAC), Païta, New Caledonia
7 - Agronomique néo-Calédonien (IAC), Mont-Dore, New Caledonia
8 - Virginia Tech University, Blacksburg, VA, USA
9 - University of Illinois, Champagne-Urbana, Urbana, IL, USA
10 - University of Alberta, Biological Sciences; Medicine (Gastroenterology), CW405 Biological Sciences, Edmonton, AB, T6G 2E9, Canada
11 - University of Georgia, 2505 Miller Plant Sciences, Plant Biology, Athens, GA, 30602, United States
Wolfe, Andrea , Stone, Benjamin , Padmalwar, Niharika , Blischak, Paul , Kubatko, Laura .
Hyobanche sanguinea (Orobanchaceae): there’s more than meets the eye.
Hyobanche (Orobanchaceae) is a small holoparasitic genus endemic to southern Africa, containing eight species. The most widespread species is H. sanguinea, distributed from coast-to-coast and from Namibia to the southern tip of Africa. Hyobanche sanguinea has a floral morphology consisting of a fused, hairy, curved and galeate corolla, and the stigma prominently exserted. Generally, if a specimen of Hyobanche met these criteria, it was designated as H. sanguinea in herbarium collections. This is partly the result of the characteristic way in which dried specimens appear – brown or black masses of stuck together flowers. Populations of Hyobanche sanguinea observed in the field have considerable morphological variation (flower color and size, inflorescence shape, pattern of sepal fusion, etc), which is consistent within a geographic region. These observations were the motivation for conducting morphological and molecular analyses to determine if H. sanguinea represents a cryptic species complex. We used AFLP markers and DNA sequences from the plastid and nuclear genomes to assess patterns of population structure and the relationships among different populations collected from across the range of H. sanguinea. Ninety-five populations representing nearly 800 individuals from all species of Hyobanche were included in the molecular analyses. Morphological observations from populations collected in each region were also made. Our results reveal that geographically distinct populations of H. sanguinea exhibit clear genetic differentiation, which is correlated with morphological differences among these populations. These findings suggest that H. sanguinea represents a complex with four or more species.
1 - Ohio State University, Department Of Ecology, Evolution, And Organismal Biology, 318 W. 12th Avenue, Columbus, OH, 43210-1293, USA
2 - Ohio State University, Evolution, Ecology, and Organismal Biology, 318 W. 12th Ave, Columbus, OH, 43210, USA
3 - Ohio State University, Evolution, Ecology and Organismal Biology, 456 Aronoff Laboratory, 318 W 12th Avenue, Columbus, OH, 43210, USA
4 - Ohio State University, Statistics, Columbus, OH, 43210, USA
Won, Hyosig , Lee, Jungho , Kim, Kyunghee , Yang, Tae-Jin , Kim, Soonok .
Comparative analysis of plastid genomes of Orobanchaceae – adding up species from Korea.
Orobanchaceae show diverse life strategies from photosynthetic autotrophs to holoparasitic heterotrophic species. To increase our understanding of plastid genome evolution, we have expanded the research of Wicke et al.(2013)’s by adding plastid genomes of 10 more species consisting 8 genera from Korea: Orobanche, Lathraea, Phacellanthus, Pedicularis, Aeginetia, Melampyrum, and Boschniakia. The complete plastid genome sequences, obtained from assembling of NGS data, ranged from 161,803(Lathraea japonica) to 56,361 (Aeginetia indica) bp, and a probable complete loss of plastid genome from Boschniakia rossica. Plastid genomes show tendency of gradual loss of genes from ndh genes, phytosystem genes, cytb group genes, RNA polymerase genes, Rubisco & ATP synthase, tRNAs, and to ribosomal proteins. Detailed results & their implications will be further discussed.
1 - Daegu University, Department of Biological Science, 201 Daegudaero, Jillyang, Gyungsan, Gyungbuk, 712-714, South Korea
2 - Green Plant Institute, B-0301, Heungdeok IT Valley, 13 Heungdeok 1-ro, Giheung, Yongin, Gyeonggi, 446-908, South Korea
3 - Seoul National University, Department of Plant Sciences, Kwanak-gu, Seoul, 151-742, South Korea
4 - Seoul National University, Department of Plant Science, Kwanak-gu, Seoul, 151-742, South Korea
5 - National Institute of Biological Resources, Biological and Genetic Resources Assessment Division, Incheon, 404-708, South Korea
Tkach, Natalia , Röser, Martin , Hoffmann, Matthias H. .
Parallel colonisation of the Arctic by plants.
The now treeless and cold region of the Arctic was covered throughout much of Tertiary with deciduous and coniferous forest. During the late Tertiary cooling and Pleistocene glacial cycles this northernmost area became available for (re)colonisation and evolution of herbaceous and shrubby plants. The present environmental conditions of the Arctic are rather detrimental for plant growth. Nevertheless, c. 2700 vascular plant species grow presently in the Arctic. These species may be simply pre-adapted immigrants from the adjacent boreal or further southern zones. On the other hand, they may have evolved in situ. To infer colonisation patterns and putative adaptations we studied the species-rich genera Artemisia L. (Asteraceae), Ranunculus L. (Ranunculaceae), and Pedicularis L. (Orobanchaceae) in a phylogenetic framework. Additionally, molecular phylogenetic studies available for other genera occurring in the Arctic were used to infer the origin of the arctic flora. The prevalent pattern observed was a parallel evolution of arctic taxa from non-arctic ancestors. The arctic taxa have evolved at different ages, sometimes even before the formation of the arctic ecosystem. The predecessors of the arctic species may have occupied different geographical places and had different ecological preferences. These were, for example, southern high mountains, steppes, forests, and wetlands. Radiations were rarely observed in the Arctic, only Douglasia (Primulaceae) and Carex (Cyperaceae) provide some examples. Morphological adaptations that may support a life in the Arctic were rarely observed.
1 - Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie, Bereich Geobotanik und Botanischer Garten, Am Kirchtor 3, Halle (Saale), 06108, Germany
2 - Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie, Bereich Geobotanik und Botanischer Garten, Am Kirchtor 3, Halle (Saale), 06108, G
Sedaghatpour, Maryam , Oldham, Karoline , Weeks, Andrea .
Microsatellite markers for estimating the population genetic diversity of the hemiparasitic wildflower, Melampyrum lineare (Orobanchaceae).
Melampyrum lineare Desr. (narrowleaf cowwheat) is a hemiparasitic, annual flowering plant native to North America. It obtains water and nutrients by penetrating the roots of its adjacent vascular host species, such as maple trees, pine trees, and members of Ericaceae. Due to this physiological dependency, M. lineare is limited to the geographical range of its hosts. Within the United States, its range extends from the southern Appalachian mountains to throughout the northeastern states and westward to Minnesota, with disjunct populations in Idaho and Montana. Within Canada, it is widely distributed at lower latitudes from Newfoundland to Vancouver Island as well as further north along the more temperate Pacific coast. In the face of a changing climate, understanding the genetic diversity of M. lineare is important for its conservation, particularly within the southern-most extent of its distribution and in US states where it is listed as rare and threatened, and for illuminating how this interdependent species tracked its host species over geological time. Thirty-two microsatellite primer pairs originally designed for Melampyrum sylvaticum, a European species, were tested on a single individual of M. lineare using a modified PCR protocol. Primer pairs, MsO66P, MsO70M, MsG2, and MsB58, amplified successfully and produced DNA fragments ranging from ca. 125 to ca. 500 base pairs. The four markers were then tested on 12 geographically distinct individuals of M. lineare from Georgia to Maine to determine allelic variation of the microsatellite regions among populations. Initial results from agarose gel electrophoresis indicated some allele size variation and heterozygosity of loci, however the DNA fragments must be sequenced to determine their precise length and base pair composition. Once this information is verified, we will then move to the final data collection stage for over 400 individuals from 50 populations of Melampyrum lineare on the East Coast of the United States as well as individuals that will be collected from Alberta and British Columbia provinces in August 2015.
1 - George Mason University , Department of Environmental Science and Policy, Fairfax, VA, 22030, USA
2 - George Mason University , School of Systems Biology, 4400 University Drive, MS 3E1, Fairfax, VA, 22030, USA
3 - George Mason University, Biology, 4400 University Dr., MSN 3E1, Fairfax, VA, 22030-4444, USA
Costea, Mihai , García, Miguel , Baute, Kurtis , Stefanović, Saša .
A complicated evolutionary history of Cuscuta pentagona clade (Convolvulaceae) and consequences of ignoring systematics.
The distribution of Cuscuta subg. Grammica, sect. Cleistogrammica (Cuscuta pentagona clade) is centered in North America (C. campestris, C. glabrior, C. harperi, C. 4pentagona, C. obtusiflora, C. plattensis, C. polygonorum, C. runyonii); however, long-distance dispersal was documented to Hawaii (C. sandwichiana), South America (C. gymnocarpa, C. stenolepis, and in part C. obtusiflora), Africa (C. bifurcata, C. schlechteri), Eurasia, and Australia (C. australis). Hybrid speciation was already documented for some members of sec. Cleistogrammica (C. sandwichiana, C. bifurcata) but previous studies strongly suggested that the extent of reticulate evolution is underestimated in Cuscuta generally, and in this section in particular. Sequence data from the nuclear internal transcribed spacer (ITS) and the plastid trnL-F region were used to reconstruct the phylogeny and gain a better understanding of the evolutionary history within the clade. Additionally, a morphometric analysis was conducted to test the phenetic distinctiveness of a select number of species with taxonomic problems: C. pentagona, C. campestris, C. gymnocarpa, and C. glabrior. Discordances between phylogenies derived from plastid and nuclear data showed that C. campestris is a hybrid, likely involving the C. runyonii/glabrior lineage as a maternal progenitor and an undiscovered species as a paternal progenitor. This latter species, an extinct or unsampled lineage, was itself inferred to be a hybrid between C. pentagona/harperi and C. australis/obtusiflora/polygonorum lineages. Both the evolutionary and morphometric results clearly showed that C. campestris is a distinct species and the negative consequences of its amalgamation with C. pentagona during the last decades are discussed. Cuscuta gymnocarpa, an enigmatic species described from specimens collected by Darwin from the Galapagos, was inferred as conspecific with C. campestris and proposed as a variety of the latter. Cuscuta campestris becomes thus one of the first documented invasive species to be introduced to the Galapagos. A new species, Cuscuta modesta, was discovered while studying the systematics of this clade.
1 - Wilfrid Laurier University, Biology, 75 University Avenue West, Waterloo, Ontario, N/A, N2L3C5, Canada
2 - University of Toronto Mississauga, Biology, 3359 Mississauga Rd., Mississauga, ON, L5L1C6, Canada
3 - Wilfrid Laurier University
4 - University Of Toronto Mississauga, Department Of Botany, 3359 Mississauga Rd, Mississauga, ON, L5L 1C6, Canada
Costea, Mihai , García, Miguel , Stefanović, Saša .
First phylogenetic classification of parasitic genus Cuscuta (dodders, Convolvulaceae).
Cuscuta (dodders, Convolvulaceae) is one of the largest and most economically important lineages of parasitic plants. The genus has a sub-cosmopolitan distribution with more than 75% of the species diversifying in the New World. The last monograph, published by Truman George Yuncker in 1932, provided a solid species-level taxonomic foundation. However, as revealed by recent phylogenetic studies, its infrageneric classification has been in great need of a taxonomic reappraisal, mainly because the morphological characters used in the previous classifications have been greatly affected by convergent evolution. Several recent phylogenetic and character evolution studies with broad sampling, as well as species-level revisions, have illustrated the deficiencies of previous classifications and provided an explicit and robust phylogenetic framework. Here we propose a new phylogenetic classification that places all 194 currently accepted species of Cuscuta into four subgenera and 18 sections. Sections have a strong morphological and biogeographical predictive value and include from one to 31 species. Thirteen section names are new or applied for the first time at the sectional rank: Babylonicae (Yunck.) M. A. Garcia, Subulatae (Engelm.) Costea and Stefanovic, Obtusilobae (Engelm.) Costea and Stefanovic, Prismaticae (Yunck.) Costea and Stefanovic, Ceratophorae (Yunck.) Costea and Stefanovic, Umbellatae (Yunck.) Costea and Stefanovic, Gracillimae Costea and Stefanovic, Californicae (Yunck.) Costea and Stefanovic, Indecorae (Yunck.) Costea and Stefanovic, Oxycarpae (Engelm. ex Yunck.) Costea and Stefanovic, Racemosae (Yunck.) Costea and Stefanovic, Partitae Costea and Stefanovic, and Denticulatae (Yunck.) Costea and Stefanovic.
1 - Wilfrid Laurier University, Biology, 75 University Avenue West, Waterloo, Ontario, N/A, N2L3C5, Canada
2 - University of Toronto Mississauga,, Department of Biology, 3359 Mississauga Rd., Mississauga, Ontario, L5L1C6, Canada
3 - University Of Toronto Mississauga, Department Of Botany, 3359 Mississauga Rd, Mississauga, ON, L5L 1C6, Canada
Urban, Joanna , Ross Friedman, Cynthia , Kaldenhoff, Ralf , Bouditchevskaia, Anastassia .
Investigation of gene expression in Arceuthobium spp. during the explosive seed dispersal with special attention to aquaporins.
Arceuthobium americanum (lodgepole pine dwarf mistletoe) is found as a pathogen of coniferous trees across North America, ultimately killing the host tree by redistributing water and nutrients from healthy areas of the tree to those infected with the parasite. Similarly, A. oxycedri (juniper dwarf mistletoe) is detrimental to Juniperus spp. (junipers) in Eurasia. Arceuthobium spp. employ a unique method of seed dispersal whereby the seed is explosively discharged from the fruit. The molecular mechanism of explosive seed discharge and, more specifically, how aquaporins and other proteins could be involved in establishing the hydrostatic pressure responsible for propelling the seed was investigated. Total RNA was extracted from fresh A. americanum as well as from A. oxycedri plants using a MasterPure™ Plant RNA Purification Kit and an RNA Easy Plant Extraction Kit with the addition of PEG, respectively, from samples collected in spring and just before the dispersal of seed (early fall). Extraction was followed by cDNA synthesis and library construction. The cDNA library was screened for aquaporins using MicroHybridization Kit; a Southern Blot was performed with a mixture of Digoxigenin-11-dUTP-labeled probes. Positive results obtained in the hybridization were sent for sequencing. Using NCBI BLAST, sequence similarity to an aquaporin PIP2:1 gene was found. Then, functional studies (stopped flow spectrophotometry) confirmed that the newly-discovered aquaporin is indeed involved in water transport. As Arceuthobium’s genome project has not yet been started and its genome isn’t sequenced, a reverse approach grounded on a heterologous array was used in which RNA from fruits of A. americanum was subjected to commercially available Arabidopsis thaliana Affymetrix gene chip analysis to probe for differences in gene expression before and during explosive seed dispersal.
1 - Thompson Rivers University, Biological Sciences, 900 McGill Rd, Kamloops, BC, V2C 2N6, Canada
2 - Darmstadt Technical University, Institute of Botany, Schnittspahnstrasse 10, Darmstadt, DE, 64237, Germany