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Distinct Evolutionary Histories Of The Dna-A And Dna-B Components Of Bipartite Begomoviruses, Rob W. Briddon, Basavaprabhu L. Patil, Basavaraj Bagewadi, Muhammad Shah Nawaz-Ul-Rehman, Claude M. Fauquet

Plant Pathology Faculty Publications

BACKGROUND: Viruses of the genus Begomovirus (family Geminiviridae) have genomes consisting of either one or two genomic components. The component of bipartite begomoviruses known as DNA-A is homologous to the genomes of all geminiviruses and encodes proteins required for replication, control of gene expression, overcoming host defenses, encapsidation and insect transmission. The second component, referred to as DNA-B, encodes two proteins with functions in intra- and intercellular movement in host plants. The origin of the DNA-B component remains unclear. The study described here was initiated to investigate the relationship between the DNA-A and DNA-B components of bipartite begomoviruses with a …

The Genome Of Nectria Haematococca: Contribution Of Supernumerary Chromosomes To Gene Expansion, Jeffrey J. Coleman, Steve D. Rounsley, Marianela Rodriguez-Carres, Alan Kuo, Catherine C. Wasmann, Jane Grimwood, Jeremy Schmutz, Masatoki Taga, Gerard J. White, Shiguo Zhou, David C. Schwartz, Michael Freitag, Li-Jun Ma, Etienne G. J. Danchin, Bernard Henrissat, Pedro M. Coutinho, David R. Nelson, Dave Straney, Carolyn A. Napoli, Bridget M. Barker, Michael Gribskov, Martijn Rep, Scott Kroken, István Molnár, Christopher Rensing, John C. Kennell, Jorge Zamora, Mark L. Farman, Eric U. Selker, Asaf Salamov, Harris Shapiro, Jasmyn Pangilinan, Erika Lindquist, Casey Lamers, Igor V. Grigoriev, David M. Geiser, Sarah F. Covert, Esteban Temporini, Hans D. Vanetten

Plant Pathology Faculty Publications

The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani), is a member of a group of >50 species known as the "Fusarium solani species complex". Members of this complex have diverse biological properties including the ability to cause disease on >100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI). Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 …

Evolution Of A Subtilisin-Like Protease Gene Family In The Grass Endophytic Fungus Epichloë Festucae, Michelle K. Bryant, Christopher L. Schardl, Uljana Hesse, Barry Scott

Plant Pathology Faculty Publications

BACKGROUND: Subtilisin-like proteases (SLPs) form a superfamily of enzymes that act to degrade protein substrates. In fungi, SLPs can play either a general nutritive role, or may play specific roles in cell metabolism, or as pathogenicity or virulence factors.

RESULTS: Fifteen different genes encoding SLPs were identified in the genome of the grass endophytic fungus Epichloë festucae. Phylogenetic analysis indicated that these SLPs belong to four different subtilisin families: proteinase K, kexin, pyrolysin and subtilisin. The pattern of intron loss and gain is consistent with this phylogeny. E. festucae is exceptional in that it contains two kexin-like genes. Phylogenetic analysis …

Evolution Of Genome Size And Complexity In Pinus., Alison M. Morse, Daniel G. Peterson, M. Nurul Islam-Faridi, Katherine E. Smith, Zenaida V. Magbanua, Saul A. Garcia, Thomas L. Kubisiak, Henry V. Amerson, John E. Carlson, C. Dana Nelson, John M. Davis

College of Agriculture & Life Sciences Publications and Scholarship

BACKGROUND: Genome evolution in the gymnosperm lineage of seed plants has given rise to many of the most complex and largest plant genomes, however the elements involved are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Gymny is a previously undescribed retrotransposon family in Pinus that is related to Athila elements in Arabidopsis. Gymny elements are dispersed throughout the modern Pinus genome and occupy a physical space at least the size of the Arabidopsis thaliana genome. In contrast to previously described retroelements in Pinus, the Gymny family was amplified or introduced after the divergence of pine and spruce (Picea). If retrotransposon expansions are responsible …

Phylogeny And Androecial Evolution In Schisandraceae, Inferred From Sequences Of Nuclear Ribosomal Dna Its And Chloroplast Dna TrnL-F Regions, Zhong Liu, Gang Hao, Yi-Bo Luo, Leonard B. Thien, Samuel W. Rosso, An-Ming Lu, Zhi-Duan Chen

Faculty Publications

Sequences of nuclear ribosomal DNA ITS and chloroplast trnL‐F regions were used to construct a phylogeny of Schisandraceae. The results show that there are two major clades in Schisandraceae. One is composed entirely of Schisandra species; the other contains a mixture of Schisandra and Kadsura species. Molecular data place Smith’s sect. Sphaerostema of Schisandra prominently within Kadsura, and thus neither Schisandra nor Kadsura is monophyletic, refuting the traditional division of the family into two genera based on morphological characters of mature fruits. The sister relationship between S. glabra (North America) and S. bicolor (China) and the monophyly of …

Differential Amplification Of Sequence Heterogeneous Ribosomal Rna Genes And Classification Of The ‘Fragaria Multicipita’ Phytoplasma, Robert E. Davis, Rasa Jomantiene, Audrone Kalvelyte, Ellen L. Dally

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Ribosomal (r) RNA interoperon sequence heterogeneity in the ‘Fragaria multicipita’ phytoplasma, a member of group 16SrVI, was initially observed in RFLP patterns of rDNA amplified in the polymerase chain reaction (PCR), and was confirmed through sequence analysis of cloned rDNA. Sequences from operons rrnA and rrnB were amplified in PCR primed by primer pair P1/P7 but from only rrnA in PCR primed by primer pair R16mF2/R16mR1. Preferential amplification of DNAfrom operon rrnA was explained by base mismatches between the R16mF2/R16mR1 primers and primer annealing sites in rrnB. The results revealed potential for classification of a phytoplasma into two …

Utility Of The Mitochondrial Cytochrome Oxidase Ii Gene For Resolving Relationships Among Black Flies (Diptera: Simuliidae), K. P. Pruess, B. J. Adams, T. J. Parsons, X. Zhu, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

The complete mitochondrial cytochrome oxidase II gene was sequenced from 17 black flies, representing 13 putative species, and used to infer phylogenetic relationships. A midge (Paratanytarsus sp.) and three mosquitoes (Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefasciatus) were used as outgroup taxa. All outgroup taxa were highly divergent from black flies. Phylogenetic trees based on weighted parsimony (a priori and a posteriori), maximum likelihood, and neighbor-joining (log-determinant distances) differed topologically, with deeper nodes being the least well-supported. All analyses supported current classification into species groups but relationships among those groups were poorly resolved. The majority of phylogenetic …

Triticeae: A Tribe For Food, Feed And Fun, Roland Von Bothmer, Björn Salomon

Herbarium Publications

Triticeae is an important tribe in the grass family, Poaceae. It contains the cereals wheat, rye, triticale, and barley as well as a large number of wild species, some of which are utilized as forage grasses. The tribe combines all kind of biological mechanisms and genetic systems: diploids and polyploids; annuals and perennials, inbreeders and outbreeders, and even apomicts. Due to this large variation Triticeae is an excellent model group for research in genetics, plant breeding, genetic diversity, taxonomy, and speciation in plants.

Triticeae is distributed in almost all temperate areas of the world and consists of some 350-450 species …

Osmophores, Floral Features, And Systematics Of Stanhopea (Orchidaceae), Kenneth J. Curry, Lorraine M. Mcdowell, Walter S. Judd, William Louis Stern

Faculty Publications

The floral fragrance glands (osmophores) of 18 species of Stanhopea and Sievekingia were examined through a series of developmental studies at light and electron microscope levels including late bud stages through postanthesis. Various characters were identified to be of potential systematic value and were recorded for each species. These characters included: texture of the osmophore surface, number of distinct cell layers comprising the osmophore, nature of lipid inclusions in osmophore cells, and presence or absence of plastoglobuli in osmophore amyloplasts. These characters were combined with traditional features of floral lip morphology for cladistic analysis. Sievekingia was the postulated outgroup. Stanhopea …