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Plant Polyadenylation Factors: Conservation And Variety In The Polyadenylation Complex In Plants, Arthur G. Hunt, Denghui Xing, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

BACKGROUND: Polyadenylation, an essential step in eukaryotic gene expression, requires both cis-elements and a plethora of trans-acting polyadenylation factors. The polyadenylation factors are largely conserved across mammals and fungi. The conservation seems also extended to plants based on the analyses of Arabidopsis polyadenylation factors. To extend this observation, we systemically identified the orthologs of yeast and human polyadenylation factors from 10 plant species chosen based on both the availability of their genome sequences and their positions in the evolutionary tree, which render them representatives of different plant lineages.

RESULTS: The evolutionary trajectories revealed several interesting features of plant polyadenylation factors. …

Arabidopsis Bhlh100 And Bhlh101 Control Iron Homeostasis Via A Fit-Independent Pathway, Alicia B. Sivitz, Victor Hermand, Catherine Curie, Grégory Vert

Dartmouth Scholarship

Iron deficiency induces a complex set of responses in plants, including developmental and physiological changes, to increase iron uptake from soil. In Arabidopsis, many transporters involved in the absorption and distribution of iron have been identified over the past decade. However, little is known about the signaling pathways and networks driving the various responses to low iron. Only the basic helix–loop–helix (bHLH) transcription factor FIT has been shown to control the expression of the root iron uptake machinery genes FRO2 and IRT1. Here, we characterize the biological role of two other iron-regulated transcription factors, bHLH100 and bHLH101, in iron homeostasis. …

Discovery Of Novel Dsrna Viral Sequences By In Silico Cloning And Implications For Viral Diversity, Host Range And Evolution, Huiquan Liu, Yanping Fu, Jiatao Xie, Jiasen Cheng, Said A. Ghabrial, Guoqing Li, Xianhong Yi, Daohong Jiang

Plant Pathology Faculty Publications

Genome sequence of viruses can contribute greatly to the study of viral evolution, diversity and the interaction between viruses and hosts. Traditional molecular cloning methods for obtaining RNA viral genomes are time-consuming and often difficult because many viruses occur in extremely low titers. DsRNA viruses in the families, Partitiviridae, Totiviridae, Endornaviridae, Chrysoviridae, and other related unclassified dsRNA viruses are generally associated with symptomless or persistent infections of their hosts. These characteristics indicate that samples or materials derived from eukaryotic organisms used to construct cDNA libraries and EST sequencing might carry these viruses, which were not easily detected by the researchers. …

Cladistic Relationships Of Aechmea (Bromeliaceae, Bromelioideae) And Allied Genera, A.P.G. De Faria, T. Wendt, Gregory K. Brown

Gregory K Brown

Aechmea (ca. 220 species) is the largest and most diverse genus in Bromelioideae (Bromeliaceae), and several dissimilar generic concepts and infrageneric classifications have been proposed, frequently involving other closely related Bromelioideae. A morphology-based phylogenetic analysis using parsimony was conducted with 86 taxa, including 52 Aechmea (7 of the 8 recognized subgenera represented) and 34 exemplars from 9 closely related genera as the ingroup. Two species of Cryptanthus were included as the outgroup. The main objectives were to assess the validity of the major infrageneric classification systems proposed for Aechmea and to elucidate the phylogenetic position of Aechmea and putatively related …

Examination Of Subfamilial Phylogeny In Bromeliaceae Using Comparative Sequencing Of The Plastid Locus Ndhf, R. G. Terry, Gregory K. Brown, R. G. Olmstead

Gregory K Brown

Parsimony analysis of 31 sequences of the chloroplast locus ndhF was used to address questions of subfamilial phylogeny in Bromeliaceae. Results presented here are congruent with those from chloroplast DNA restriction site analysis in recognizing a clade containing Bromelioideae and Pitcairnioideae, and in resolving Tillandsioideae near the base of the family. Placements of several taxonomically difficult genera (e.g., Glomeropitcairnia and Navia) corroborate those of traditional treatments; however, these data suggest that Brocchinia (Pitcairnioideae) is the sister group to the remainder of Bromeliaceae. Further evidence for the paraphyly of Pitcairnioideae includes the resolution of Puya as the sister group to Bromelioideae. …

Evolutionary Genomics Of Mycovirus-Related Dsrna Viruses Reveals Cross-Family Horizontal Gene Transfer And Evolution Of Diverse Viral Lineages, Huiquan Liu, Yanping Fu, Jiatao Xie, Jiasen Cheng, Said A. Ghabrial, Guoqing Li, Youliang Peng, Xianhong Yi, Daohong Jiang

Plant Pathology Faculty Publications

BACKGROUND: Double-stranded (ds) RNA fungal viruses are typically isometric single-shelled particles that are classified into three families, Totiviridae, Partitiviridae and Chrysoviridae, the members of which possess monopartite, bipartite and quadripartite genomes, respectively. Recent findings revealed that mycovirus-related dsRNA viruses are more diverse than previously recognized. Although an increasing number of viral complete genomic sequences have become available, the evolution of these diverse dsRNA viruses remains to be clarified. This is particularly so since there is little evidence for horizontal gene transfer (HGT) among dsRNA viruses.

RESULTS: In this study, we report the molecular properties of two novel dsRNA mycoviruses that …

Systematics Of Harrisia (Cactaceae), Alan R. Franck

USF Tampa Graduate Theses and Dissertations

The genus Harrisia Britton (Cactaceae) comprises species of columnar cacti that are united by a unique seed morphology. The species range in form from prostrate shrubs to large trees and are native to South America and the Caribbean region. Harrisia is placed in an unresolved position within subtribe Trichocereinae of tribe Cereeae of subfamily Cactoideae. Relationships among the species within Harrisia are also poorly understood. In this study, several species of Harrisia were sequenced for as many as seven different regions of nuclear and plastid DNA. Species in the Caribbean were also examined with amplified fragment length polymorphisms. The morphology …

Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal

Madhav Nepal

Evolution Of Plant Sucrose Uptake Transporters, Anke Reinders, Alicia B. Sivitz, John M. Ward

Dartmouth Scholarship

In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were …

Diploid Allium Ramosum From East Mongolia: A Missing Link For The Origin Of The Crop Species A. Tuberosum?, Batlai Oyuntsetseg, Frank R. Blattner, Nikolai Friesen

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

In eastern Mongolia, a diploid close relative of the tetraploid (4x) crop species Allium tuberosum and its closest wild relative A. ramosum (4x) was found and characterized by karyotype analysis and with molecular marker techniques. An earlier analyses revealed A. ramosum to be sister of the crop but excluded it as its progenitor. At that time a putative diploid cytotype of A. ramosum was hypothesized as a potential progenitor taxon of the tetraploids. New phylogenetic analyses of chloroplast and nuclear DNA sequences including the recently found cytotype (A. aff. tuberosum) together with A. tuberosum and A. ramosum accessions …

Morphological Cladistic Analysis Of Some Bifurcate Hairy Sections Of Astragalus (Fabaceae) In Iran, Reza Sheikh Akbari Mehr, Ali Asghar Maassoumi, Abbas Saidi, Shahrokh Kazempour Osaloo, Majid Ghorbani Nohooji

Turkish Journal of Botany

The phylogenetic relationships among some bifurcate hairy sections of Astragalus L. were reconstructed using 38 vegetative and reproductive morphological characters. A data matrix comprising 36 ingroups and 2 outgroups was analysed using the maximum parsimony method. The present results revealed that sections Onobrychoidei DC. and Ornithopodium Bunge are interrelated taxa and form a single monophyletic group. The current status of section Dissitiflori DC. is a nonmonophyletic group. Its members form several subclades and unresolved branches across the tree. Sections Erioceras Bunge and Cytisodes Bunge as well as Corethrum Bunge are sister taxa and form weakly to highly supported monophyletic groups, …