Life Sciences Commons^™

Tetrameric Photosystem I: From Initial Discovery And Characterization In Chroococcidiopsis Sp. Ts-821 To Exploration Of Its Distribution And Understanding Of Its Significance In Cyanobacteria, Meng Li

Doctoral Dissertations

Photosystem I (PSI) forms trimeric complexes in most characterized cyanobacteria. We had reported the tetrameric form of PSI in the unicellular cyanobacterium, Chroococcidiopsis sp. TS-821 (TS-821). Using Cryo-EM, a 3D model of the PSI tetramer structure at 11.5 [Angstrom] resolution was obtained and a 2D map within the membrane plane of at 6.1 [Angstrom]. In contrast to the three-fold symmetry in trimeric PSI crystal structure from T. elongatus, two different inter-monomer interactions involving PsaLs are found in the PSI tetramer. Phylogenetic analysis based on PsaL protein sequences shows that TS-821 is closely related to heterocyst-forming cyanobacteria. Additionally, this tetrameric …

Investigating Genetic Differences Between Strains Of Janthinobacterium Lividum On Salamanders And In Their Environment, Rhiannon E. Black

Chancellor’s Honors Program Projects

No abstract provided.

Systematics, Diversity And Evolution Of The Suborder Tricholomatineae (Agaricales), Marisol Sanchez Garcia

Doctoral Dissertations

The suborder Tricholomatineae is one of the several major groups of Agaricales, the largest order of mushroom-forming fungi. This suborder contains three families: Tricholomataceae, Entolomataceae and Lyophyllaceae, as well as many genera of incertae sedis. Members of the Tricholomatineae exhibit variation in nutritional mode, including mycoparasites, saprotrophs, termite-associates, bryophyte parasites, and ectomycorrhizal (ECM) symbionts, which makes the clade ideal for studying trophic evolution in fungi from a phylogenetic perspective.

This dissertation combines taxonomy and evolutionary analyses to contribute to the knowledge of fungal diversity and mycorrhizal evolution. First, I present a systematic revision of the family Tricholomataceae within a …

Computational Identification Of Terpene Synthase Genes And Their Evolutionary Analysis, Qidong Jia

Doctoral Dissertations

Terpenoids, the largest and most structurally and functionally diverse class of natural compounds on earth, are mostly synthesized by plants to be involved in various plant environment interactions. Some terpenoids are classified as primary metabolites essential for plant growth and development. Terpene synthases (TPSs), the key enzymes for terpenoid biosynthesis, are the major determinant of the tremendous diversity of terpenoid carbon skeletons. The TPS genes represent a mid-size family of about 30-100 functional genes in almost all major sequenced plant genomes. TPSs are also found in fungi and bacteria, but microbial TPS genes share low levels of sequence similarity and …

Biochemistry And Evolution Of The Phytohormone-Methylating Sabath Methyltransferase In Plants, Minta Chaiprasongsuk

Doctoral Dissertations

Known members of Phytohormone-methylating compounds are plant synthesis compounds that serve as attractants of other living organisms beneficial to the plants or as defense against other biotic as well as abiotic agents. To increase their fitness and survival in a stressful environment plants produce distinct sets of phytohormone-methylating compounds. Plant genomes can encode the necessary enzymes to acquire the ability to make new specialized compounds during evolution. This dissertation aims to investigate the biochemical and biological functions and evolution of SABATH genes in different lineages of plants. Black cottonwood, Brachypodium and Norway spruce genome were used as the model for …

Using Phylogenetics To Understand The Evolutionary Relationships Of Hibiscus Section Furcaria, Whitaker Matthew Hoskins

Masters Theses

Neopolyploids constitute at least 35% of known species of angiosperms, and because polyploidization is a pertinent process in plant diversification and domestication, it is a thriving field of study. Hibiscus section Furcaria includes several groups of polyploids in addition to ten known diploid species. In previous studies genome groups for Hibiscus section Furcaria were determined through artificial hybridization experiments and patterns of biogeography were elucidated based on the distribution of diploids and polyploids. For instance, the Australian hexaploids contain 3 genomes (designated G, J, and V) and are thought to have developed from a polyploidization event between an African diploid …