This dissertation presents the result of two separate research programs. The first elucidates the phylogeny, biogeography and systematics of the genus Menodora in the olive family. A phylogeny based on the internal transcribed spacer (ITS) of nuclear ribosomal DNA and the chloroplast rps16 and trnL introns and trnL-F intergenic spacer demonstrates that the genus is monophyletic. Within the genus, M. robusta of Patagonia is the first taxon to branch, followed by a monophyletic African clade and M. spinescens of California, though the placement of the latter does not have strong support. Most North American species are nested within the derived South Americans. A South American origin is hypothesized, with two independent dispersals to North America, and a single dispersal to Africa. The phylogeny provided new insights for the systematic treatment, where 24 species, one subspecies and six varieties are recognized, with major realignments of the intregrifolia and scabra species complexes, and a single new species described. In the second area of research, the chloroplast genome of Pelargonium × hortorum has been completely sequenced. At 217,942 base pairs (bp), it is both the largest and most rearranged land plant chloroplast genome yet sequenced. It features two copies of a greatly expanded inverted repeat (IR) of 75,741 bp each, and diminished single copy regions of 59,710 bp and 6,750 bp. Gene content is similar to other angiosperms, with the exceptions of a large number of pseudogenes, two open reading frames (ORF56 and ORF42), and the losses of accD, trnT-ggu, and possibly rpoA. The latter may be represented, however, by highly divergent set of rpoA-like ORFs. The IR expansion accounts for most of the size increase of the genome, but an additional 10% is related to the large number of repeats found. Most of these occur near rearrangement hotspots, and two different repeat associations (characterized by full or partial duplications of several genes) are localized in these regions. We propose simple models that account for the major rearrangements with a minimum of eight IR boundary changes and 12 inversions in addition to several sequence duplications. / text

Penstemon is one of North America's largest endemic genera with over 280 described species. These species are distributed throughout most of North America from the Arctic northern latitudes to tropics of Central America. The genus has historically been divided into six subgenera, but has recently been reorganized into two subgenera following some recent phylogenetic studies. I made a comprehensive assessment of the Penstemon genus' geographic distribution utilizing herbaria databases by ecoregion to discuss the general ecologic adaptations of each historic subgenera. I also assessed the Penstemon genus' bee pollinator diversity utilizing online databases of bee specimen collections associated with Penstemon flowers. I investigated the efficacy of utilizing the plastid genomes (plastomes) of 29 species in the Lamiales order, including five newly sequenced Penstemon plastomes, for analyzing phylogenetic relationships and resolving problematic clades. I compared whole-plastome based phylogenies to phylogenies based on individual gene sequences (matK, ndhF, psaA, psbA, rbcL, rpoC2, and rps2) and concatenated sequences. I found that my whole-plastome based phylogeny had higher nodal support than all other phylogenies, which suggests that it provides greater accuracy in describing the hierarchal relationships among taxa as compared to other methods. I found that the genus Penstemon forms a monophyletic clade sister to, but separate from, the Old World taxa of the Plantaginaceae family included in our study. My whole-plastome based phylogeny also supports the rearrangement of the Scrophulariaceae family and improves resolution of major clades and genera of the Lamiales. I evaluated 16 accessions of P. cyaneus with 14 accessions of closely related Penstemon species in common garden in two distinct environments in Aberdeen, ID and Provo, UT during 2018 and 2019. I evaluated the accessions for key commercial seed production traits including survival, plant height, number of stems, and seed production. Both common gardens received supplemental irrigation during 2018, but I withheld irrigation during 2019. Plant survival in our Aberdeen, ID site was not significantly different between years, but survival was a significantly lower in 2019 than in 2018 at our Provo, UT site. The mean survival for P. cyaneus accessions ranged from 56% to 94%, and the mean seed production ranged from 91.2 kg/ha to 397.6 kg/ha. I recommend developing a commercial seed source derived from pooling germplasm of six accessions (PECY3-367, PECY3-371, PECY3-376, PECY3-443, PECY3-457, and PECY3-458). These accessions had mean survival rates of 82-94%, and seed production of 196.2-397.6 kg/ha.

Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-11-07T16:30:36Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Evelise Carvalho.pdf: 2321912 bytes, checksum: 3957e800afc8b54ee2d2bc427c9dffd6 (MD5) / Made available in DSpace on 2016-11-07T16:30:36Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Evelise Carvalho.pdf: 2321912 bytes, checksum: 3957e800afc8b54ee2d2bc427c9dffd6 (MD5) Previous issue date: 2015-05-19 / Algas verdes da classe Trebouxiphyceae estão entre os organismos presentes no continente Antártico, onde a espécie mais relatada é a macroalga verde Prasiola crispa (Lightfoot) Kützing. Considerada um organismo extremófilo, pois se desenvolve com muito sucesso no habitat extremo da Antártica, ainda são raros na literatura dados moleculares sobre esta espécie, o que impede uma avaliação sobre sua taxonomia e posição filogenética. Com o advento das tecnologias de sequenciamento de nova geração, os genomas de organelas tornaram-se uma grande ferramenta para estudos de filogenia, pois fornecem inúmeros dados filogenéticos, sequências de proteínas e nucleotídeos e também informações sobre conteúdo gênico e arquitetura. Neste trabalho, foi determinada a sequência dos genomas do cloroplasto (cpDNA) e mitocondrial (mtDNA) de P. crispa, com o intuito de inferir as relações evolutivas deste organismos com outras espécies de plantas verdes, bem como uma análise estrutural. Os genomas plastidial e mitocondrial foram sequenciados por Macrogen Service (SolexaIllumina Hi-Seq 2500). A montagem, anotação, alinhamento, construção da filogenia e análise sintênica foram realizados in silico com softwares específicos. O cpDNA e mtDNA P. crispa apresentam 196.502 pb e 89.819 pb, respectivamente. Estes genomas acessórios apresentam 21 genes putativos relacionados com a fotossíntese e 18 genes relacionados com o metabolismo oxidativo. A análise filogenômica baseada no cpDNA demonstrou que P. crispa agrupou com alga trebouxiophyceae Prasiolopsis sp. formando o clado Prasiola juntamente com Stichococcus bacilaris. Nossos resultados para filogenômica embasada no mtDNA revelam que P. crispa agrupa com as outras espécies da classe Trebouxiphyceae. A análise de sintenia do cpDNA e mtDNA de P. crispa com a espécies de plantas verdes relacionadas evolutivamente demonstram que estes organismos apresentam poucos blocos gênicos sintênicos. Este trabalho pioneiro com a alga P. crispa, demonstra que os genomas acessórios suprem uma gama de dados moleculares que podem ser utilizados para estudos filogenômicos. Além disto, as informações geradas a partir do sequenciamento do cpDNA e mtDNA de P. crispa fornecem um aporte para estudos futuros mais aprofundados / Green algae from Trebouxiophyceae class are among the organisms in the Antarctic continent, where the most reported species is the green macroalga Prasiola crispa (Lightfoot) Kützing. This algae is considered an extremophile organism because develops successfully in the harsh Antarctic habitat, however studies reporting molecular data of this species are still lacking in the literature, which prevents an assessment of their correct taxonomy and phylogenetic position. With the advent of next generation sequencing technologies, it because easier to obtain molecular information as for example from organelle genomes making them a great tool for taxonomic studies because they provide a great number of, phylogenetic data, nucleotides, protein sequences, gene content and architecture information. In this study, we determined the sequence of the chloroplast (cpDNA) and mitochondrial (mtDNA) genome of P. crispa in order to infer the evolutionary relationships of the organisms with other species of green plants, as well as a structural analysis. Plastid and mitochondrial genome was sequenced by Macrogen Service (Illumina Solexa Hi-Seq 2500). The genome assembly, annotation, sequences alignment, phylogeny construction, and structural analyses were performed in silico with specific softwares. Plastid and Mitochondrial genomes have a total length of 196,502 bp and 89,819 bp, respectively. These genomes presented 21 putative photosynthesis related genes and 18 oxidative metabolism related genes, respectively. Phylogenetic analysis based on the cpDNA demonstrated that P. crispa grouped with Trebouxiophyceae algae Prasiolopsis sp. forming the Prasiola clade along with Stichococcus bacilaris. Our results for phylogenetic analysis grounded in mtDNA show that P. crispa groups with other species of Trebouxiphyceaen alga. Synteny analysis of P. crispa cpDNA and mtDNA with evolutionarily related species of green plants shows that these organisms have few syntenic gene blocks. This pioneering work with P. crispa provided the accessories genomes which suppled a range of molecular data that can be employed to taxonomic studies. In addition, the information generated from the sequencing of cpDNA and mtDNA of P. crispa provide a contribution for further studies.

La stabilité génomique des organelles de plantes suscite un grand intérêt dans le domaine de la biologie végétale. En effet, plusieurs études récentes suggèrent que ce type d’instabilité génomique pourrait mener à l’isolation de traits intéressants en l’agronomie. Plusieurs protéines sont d’ailleurs déjà été identifiés comme étant impliqués dans le maintien de la stabilité de ces génomes, tels que MSH1, la famille des POLI, OSB1, les protéines Whirly et les Recombinases A (RECA). Le génome nucléaire d’Arabidopsis thaliana encode trois protéines s’apparentant à la Recombinase A bactérienne et qui sont ciblées à la mitochondrie et/ou au chloroplaste, soit RECA1, RECA2 et RECA3. Globalement, ces gènes partagent une similarité de séquence de 61% avec leur homologue bactérien chez Escherichia coli. Chez les bactéries ces protéines jouent un rôle essentiel dans la recombinaison homologue et sont impliquées dans la réparation de l’ADN. Chez Arabidopsis, il a été démontré que RECA2 et RECA3 sont nécessaires au maintien de l’intégrité du génome mitochondriale. Toutefois leur contribution à la stabilité du génome chloroplastique ainsi que le rôle de RECA1 restent obscures. Le but de ce projet est donc de déterminer la contribution éventuelle des protéines RECA d’Arabidopsis dans la réparation de l’ADN chloroplastique et plus précisément le rôle du gène RECA1. Nous énonçons l’hypothèse que les RECA de plantes se comportent effectivement comme leurs orthologues bactériens en étant impliqués dans la recombinaison homologue. Dans le cadre de ce projet, nous avons tenté d’isoler des lignées mutantes pour chacun des gènes RECA d’Arabidopsis. En somme, nous avons pu obtenir des lignées convenables pour notre étude que dans le cas du gène RECA1. Ces lignées ont été utilisées pour évaluer la contribution de ce gène à la stabilité du génome du chloroplaste. Ensuite, pour étudier la relation épistatique des gènes RECA1, WHY1 et WHY3, un croisement des différentes lignées mutantes pour ces gènes a été réalisé. Nous avons ensuite étudié la sensibilité de toutes ces lignées mutantes à la ciprofloxacine, un agent causant des bris double brin exclusivement dans les organelles de plantes. Finalement, iii nous avons testé la présence de réarrangements dans le génome du chloroplaste en condition normal ou en présence de stress génotoxique. Nos résultats démontrent que les protéines Whirly et RECA1 sont impliquées dans deux voies de réparation de l’ADN différentes et que les Whirly sont suffisantes pour s’occuper des bris d’ADN double brin en l’absence de RECA1. Nous démontrons également que l’absence de Whirly et RECA1 entraine une forte augmentation de la quantité de réarrangements dans le génome du chloroplaste. De plus nous proposons que la polymérase POLIB est impliquée dans la même voie de réparation que RECA1. Finalement nous proposons un modèle pour expliquer nos résultats et impliquons RECA1 dans un mécanisme de réparation d’ADN et aussi un rôle potentiel dans la réplication. / The stability of plant organelles genomes elicits a great interest in the domain of plant biology. In fact, numerous studies suggest that genomic instability can lead to the isolation of interesting traits in the field of agronomy. Some factors such as MSH1, the POLI family, OSB1, the Whirly proteins and the Recombinase A (RECA), have already been identified has being implicated in the maintenance of genome stability. The nuclear genome of Arabidopsis thaliana encodes three proteins, RECA1, RECA2 and RECA3, that shares a high resemblance with bacterial Recombinase A. They are targeted to the mitochondria and/or to the chloroplast. Globally, these genes share a similarity of sequence of 61% with their bacterial homologue in Escherichia coli. In bacteria these proteins play an essential part in homologous recombination and are implicated in DNA repair. In Arabidopsis, RECA2 and RECA3 have been shown as being essential to maintain the integrity of the mitochondrial genome but their contribution to the stability of the chloroplast as well as the role of RECA1 remains obscure. The goal of this project is to establish the eventual contribution of the Arabidopsis RECA proteins in the repair of chloroplast DNA and more precisely the role of the RECA1 gene. We propose the hypothesis that plants RECA act in the same fashion as their bacterial orthologues by being implicated in homologous recombination. Within the framework of this project, we have attempted to isolate mutant lines for each RECA gene of Arabidopsis. In the end, we were able to obtain appropriate lines for our study only for the RECA1 gene. These lines were then used to evaluate the contribution of the gene to chloroplast genome stability. Afterwards, in order to study the epistatic relationship between the RECA1, WHY1 and WHY3 genes, a cross between different mutant lines of these genes was realised. We then studied the sensitivity of all of those mutant lines to ciprofloxacine, an agent causing double stranded breaks exclusively in plant organelles. Finally, we evaluated the presence of rearrangements in the chloroplast genome under normal conditions and under the presence of a genotoxic stress. Our v results show that the Whirly and RECA1 proteins are implicated in two separate pathways of DNA reparation and that the Whirly proteins are sufficient to take in charge DNA double strand breaks generated by the absence of RECA1. We also demonstrate that the absence of Whirly and RECA1 causes an increasein the quantity of rearrangements in the chloroplast genome. Furthermore, we propose that the polymerase POLIB is implicated in the same repair pathway as RECA1. Finally we propose a model to explain our results and implicate RECA1 in a DNA repair mechanism and propose a role for RECA1 in DNA replication.

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