Project description:Because plants are immobile, they have developed intricate mechanisms to sense and absorb nutrients, adjusting their growth and development accordingly. Sulfur is an essential macroelement, but our understanding of its metabolism and homeostasis is limited. LSU (RESPONSE TO LOW SULFUR) proteins are plant-specific proteins with unknown molecular functions and were first identified during transcriptomic studies on sulfur deficiency in Arabidopsis. These proteins are crucial hubs that integrate environmental signals and are involved in the response to various stressors. Herein, we report the direct involvement of LSU proteins in primary sulfur metabolism for the first time. Our findings revealed that the quadruple lsu mutant, q-lsu-KO, which was grown under nonlimiting sulfate conditions, exhibited a molecular response resembling that of sulfur-deficient wild-type plants. This led us to explore the interactions of LSU proteins with sulfate reduction pathway enzymes. We found that all LSU proteins interact with ATPS1 and ATPS3 isoforms of ATP sulfurylase, all three isoforms of adenosine 5´phosphosulfate reductase (APR), and sulfite reductase (SiR). Additionally, in vitro assays revealed that LSU1 enhances the enzymatic activity of SiR. These results highlight the supportive role of LSU proteins in the sulfate reduction pathway.
Project description:The purpose of this experiment was to assess the effect of a synergistic combination of natural pyrethrin and an ethylacetate extract of Piper nigrum seeds (a botanical insecticide). This effect was compared to the effects of P. nigrum or pyrethrin used alone. Due to the synergistic nature of the mixture, it was predicted that gene expression profiles in this treatment would reflect this effect. Keywords: insecticide response, stress-response
Project description:BackgroundDinoflagellates represent a major lineage of unicellular eukaryotes with unparalleled diversity and complexity in morphological features. The monophyly of dinoflagellates has been convincingly demonstrated, but the interrelationships among dinoflagellate lineages still remain largely unresolved. Warnowiid dinoflagellates are among the most remarkable eukaryotes known because of their possession of highly elaborate ultrastructural systems: pistons, nematocysts, and ocelloids. Complex organelles like these are evolutionary innovations found only in a few athecate dinoflagellates. Moreover, the taxonomy of warnowiids is extremely confusing and inferences about the evolutionary history of this lineage are mired by the absence of molecular phylogenetic data from any member of the group. In this study, we provide the first molecular phylogenetic data for warnowiids and couple them with a review of warnowiid morphological features in order to formulate a hypothetical framework for understanding character evolution within the group. These data also enabled us to evaluate the evolutionary relationship(s) between warnowiids and the other group of dinoflagellates with complex organelles: polykrikoids.ResultsMolecular phylogenetic analyses of SSU and LSU rDNA sequences demonstrated that warnowiids form a well-supported clade that falls within the more inclusive Gymnodinium sensu stricto clade. These data also confirmed that polykrikoids are members of the Gymnodinium sensu stricto clade as well; however, a specific sister relationship between the warnowiid clade and the polykrikoid clade was unresolved in all of our analyses. Nonetheless, the new DNA sequences from different isolates of warnowiids provided organismal anchors for several previously unidentified sequences derived from environmental DNA surveys of marine biodiversity.ConclusionComparative morphological data and molecular phylogenetic data demonstrate that the polykrikoid and the warnowiid clade are closely related to each other, but the precise branching order within the Gymnodinium sensu stricto clade remains unresolved. We regard the ocelloid as the best synapomorphy for warnowiids and infer that the most recent common ancestor of polykrikoids and warnowiids possessed both nematocysts and photosynthetic plastids that were subsequently lost during the early evolution of warnowiids. Our summary of species and genus concepts in warnowiids demonstrate that the systematics of this poorly understood group is highly problematic and a comprehensive revision is needed.
Project description:Data-dependent LC-MS/MS was used to generate a protein inventory of an affinity-purified assembly intermediate of the small subunit (SSU) of the Trypanosoma brucei mitochondrial ribosome. The identified proteins (mitoribosomal proteins and putative maturation factors) were then used to assist in solving the structure of the SSU assemblosome by cryo-electron microscopy.
Project description:Nicotiana attenuata and Solanum nigrum were challenged with different insects: Manduca sexta and Tupiocoris notatus in different combinations Goals of the study are first to haracterize the transcriptional response of two native Solanaceous plants (Nicotiana attenuata and Solanum nigrum) to attack from two herbivorous pests common on Solanaceous crops (Manduca sexta and Tupiocoris notatus). And second to identify genes involved in herbivore vaccination phenomenon. After germination, inbred and genetically characterized lines of N. attenuata DI92 and S. nigrum Sn30 originally collected from southwestern Utah in 1988, and Jena Germany in 2000, respectively, were grown in a greenhouse. Eggs of Manduca sexta (abbreviated M. s.) came from the North Carolina State University - Entomology Insectary and were hatched under 37°C. Nymphs and adults of Tupiocoris notatus (abbreviated T. n.) came from laboratory colonies started in 2000 with individuals collected from our Utah field sites. Plant were challenged with these different insect and combinations of them. All plants for a given treatment were enclosed in glass-and-mesh insect cages to avoid cross-infection. After 24 h or 5 days the herbivores and their frass were removed, and the above ground biomass of each plant was flash-frozen in liquid nitrogen and stored at -80 °C until RNA extraction. Three independent replicate cages (biological replicates) were used for each of the 7 treatments resulting in a total of 21 cages per species. RNA extraction was performed according to the protocol using Trizol. The RNA samples represent a pooled sample from 4 plants grown in a cage. Keywords: Direct comparison