Showing 1 - 10 of 11 Items
Identification of Mutations in WAK Locus in Arabidopsis thaliana Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2017-05-01
Creator: Arman Ashrafi
Access: Access restricted to the Bowdoin Community
The Role of the Golgi ELMO Proteins in Cell Adhesion in Arabidopsis thaliana
Date: 2021-01-01
Creator: Wesley James Hudson
Access: Open access
- Proper growth and development of plant cells is dependent upon successful cell adhesion between cells, and this is mostly mediated by pectin in the plant cell wall. Previously, the Kohorn Laboratory identified a non-enzymatic Golgi protein named ELMO1 as it is required for cell adhesion, likely acting as a scaffold for cell wall polymer synthesis. Plants with mutant ELMO1 demonstrate a weak defective cellular adhesion phenotype as well as reduced mannose content in the cell wall. ELMO1 has homologous proteins in at least 29 different vascular plants. These homologues have 2 possible deletions in their amino acid sequence, but protein modeling determined that these variations will not affect protein structure. There are 5 homologous ELMO1 proteins in Arabidopsis thaliana that have been aptly named ELMO2, ELMO3, ELMO4, ELMO5. elmo2-/-mutants revealed no mutant adhesion phenotypes, while elmo1-/-elmo2-/-double mutants revealed strong defects in adhesion. Confocal microscopy of propidium iodide-stained seedlings confirmed the lack of a phenotype for elmo2-/-mutants and showed disorganized gapping cells for the elmo1-/-elmo2-/-mutant. Additionally, while elmo2-/-did not have any change to root or hypocotyl length, elmo1-/-elmo2-/- mutants were significantly shorter in both regards. Taken together, these data support that ELMO2 and ELMO1 are partially redundant.
The EOL Enhancer Activates Eya Expression to Mediate Visual System Development in Drosophila melanogaster This record is embargoed.
- Embargo End Date: 2027-05-16
Date: 2024-01-01
Creator: Benjamin Sewell-Grossman
Access: Embargoed
Investigating the Role of Heterochromatin Protein 1 (HP1) in the Formation of Chromosome Compartments Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2025-06-01
Date: 2020-01-01
Creator: Diego Andres Villamarin
Access: Access restricted to the Bowdoin Community
Identification of MPKs Involved in the Wall Associated Kinase Regulated Stress Response in Arabidopsis thaliana Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2013-05-01
Creator: Patrick J Lariviere
Access: Access restricted to the Bowdoin Community
Genetic Analysis of Adhesion Protein ELMO3 in Arabidopsis thaliana
Date: 2022-01-01
Creator: Garrison Asper
Access: Open access
- The Extracellular Matrix (ECM) between plant cells is vital for structure, development, and intercellular adhesion. A pectin rich layer in between cells, the middle lamella, is largely responsible for regulating the adhesive properties of adjacent plant cells. Homogalacturonan (HG) pectin, the most common, is synthesized in the Golgi and secreted into the ECM where it undergoes calcium crosslinking, increasing its adhesive properties. Mutations in proteins essential for HG synthesis can reveal a severe adhesion defective phenotype, where the hypocotyls of dark grown Arabidopsis exhibit cell sloughing, curling, and general disorganization. A family of five ELMO proteins are suspected to act as scaffolds for pectin biosynthesis enzymes. ELMO1 and ELMO4 mutants exhibit an adhesion deficient phenotype, and a double mutant provides evidence of redundancy in function between ELMO1 and ELMO2. ELMO1-GFP co-immunoprecipitated with enzymes required for HG synthesis indicating its role as a scaffold protein. Double mutants of the other ELMO homologues were created to determine if they exhibit functional redundancy, and ELMO1 and ELMO3 appear partially redundant. A gene deletion of ELMO3 was also created using the CRSPR/Cas9 system, resulting in two distinct elmo3 deletion alleles, which were phenotypically identical to the original elmo3-/- mutant. All adhesion defective phenotypes can be partially suppressed by altering the osmoticum and hence turgor that provides pressure on adhesive cells. Lastly, ELMO3-GFP was localized to the Golgi, the site of pectin biosynthesis, further supporting a common role of the ELMOs in pectin biosynthesis.
The Roles of ROG1, REM1, and REM2 in a WAK Mediated Pectin Response Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2015-05-01
Creator: Joshua A Benton
Access: Access restricted to the Bowdoin Community
Examining the role of GRP and LIK1 in Wall Associated Kinase (WAK) perception of pectin in the plant cell wall
Date: 2017-01-01
Creator: Jack Ryan Mitchell
Access: Open access
- Wall associated kinases (WAKs) are cell membrane bound receptor kinases that bind pectin and pectin fragments (OGs).The binding of WAKs to pectin sends a growth signal required for cell elongation and plant development. WAKs bind OGs with higher affinity than native pectin and instead activate a stress response. Glycine rich proteins (GRPs) are secreted cell wall proteins of unknown function. Seven GRPs with 65% sequence similarity are coded on a 90kb locus of Arabidopsis chromosome 2. GRP3 and WAK1 have been shown to bind in vitro, but single null mutations have no discernible phenotype, suggesting that the GRPs are redundant. Low recombination frequency has made multiple mutations difficult to achieve, but in this thesis, CRISPR/Cas9 technology was used to induce deletions of the GRP locus. The promoters pYAO and pICU2 drove Cas9 expression in transformed Arabidopsis plants. The presence of a deletion and Cas9 were detected by PCR. While somatic mutations were induced, there was no inheritance of the GRP deletion, indicating that pYAO and pICU2 do not drive Cas9 to induce deletions in progenitor cells. LIK1 is a CERK1 interacting kinase implicated in mediating response to various microbe associated molecular patterns (MAMP) such as chitin, flagellin, and peptidoglycans. LIK1 exhibits a drastic increase in phosphorylation in response to OG treatment, making it a candidate for a co-receptor to WAK. T-DNA insertions to the 5’UTR of LIK1 were used to examine the effect of a lik1 mutation on the OG induced stress response. lik1/lik1 mutant seedlings were grown in the presence and absence of OGs, and RNA was isolated. qPCR was used on cDNA to examine FADLOX expression, a reporter for the transcriptional response to OGs. The lik1/lik1 mutant caused a reduction in the OG induced transcriptional response. However, increased LIK1 expression was associated with the T-DNA insertion indicating that LIK1 inhibits the WAK stress response pathway. Understanding the roles of GRP and LIK1 in moderating WAK mediated pathogenic response in Arabidopsis will enable a better understanding of plant resistance to pathogen invasion in the greater plant kingdom.
Testing conservation of an mRNA transport pathway in yeast Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Kyu Young "Kevin" Chi
Access: Access restricted to the Bowdoin Community
The Role of Pectin Methyl Esterase in Pectin Activation of WAK Regulated Stress Response in Arabidopsis thaliana Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Nicholas J Saba
Access: Access restricted to the Bowdoin Community