Showing 51 - 60 of 63 Items

Date: 2023-01-01
Creator: Margaret Elizabeth Weinstock
Access: Access restricted to the Bowdoin Community

- Embargo End Date: 2027-05-15
Date: 2024-01-01
Creator: Victoria Dunphy
Access: Embargoed

Date: 2020-01-01
Creator: Brendan H. Pulsifer
Access: Access restricted to the Bowdoin Community
Date: 2021-01-01
Creator: Andrew Close Bolender
Access: Open access
- Plant cell adhesion is mediated by the extracellular matrix (ECM) or cell wall and plays an important role in plant morphogenesis and development. The amount, modification, and cleavage of pectin in the cell wall are major contributors to the adhesive properties of the ECM. To gain a more complete picture of plant cell adhesion processes, Arabidopsis thaliana seedlings were previously mutagenized and screened for hypocotyl adhesion defects. Genomic sequencing of one plant exhibiting an adhesion defect, isolate 242, showed that two mutations, one in cellulose synthase (CesA1) and another in a sugar transporter, are candidates for the causative mutation. This thesis reports that CesA1 is necessary for proper plant cell adhesion, while the sugar transporter encoded at At4g32390 is not. Dark grown seedlings homozygous for mutations in CesA1 stain in ruthenium red, indicating atypical adhesion, while those homozygous for null mutations in At4g32390 do not. Previous study of another adhesion mutant revealed ELMO1, a Golgi protein necessary for plant cell adhesion, and four additional homologs ELMO2-5 in the A. thaliana genome. Two of these homologs, ELMO2 and ELMO3, fused to GFP, colocalized with mCherry-MEM1 markers in the Golgi, but not mCherry-NLM12 ER markers, indicating that ELMO2 and ELMO3 are also Golgi proteins.

Date: 2020-01-01
Creator: Ilana R. Olin
Access: Access restricted to the Bowdoin Community

Date: 2021-01-01
Creator: Chiamaka Doris Okoye
Access: Access restricted to the Bowdoin Community

Date: 2021-01-01
Creator: Kyu Young "Kevin" Chi
Access: Access restricted to the Bowdoin Community
Date: 2022-01-01
Creator: Isabel Kristina Ball
Access: Open access
- Plant cell growth and development relies on proper cellular adhesion. As the extracellular matrix serves as the area of connection between two cells, its synthesis and maintenance are essential for cellular adhesion. The middle lamella region, the layer of the extracellular matrix between two adjacent cell walls, is diffuse with the polysaccharide pectin due to its delivery by Golgi vesicles early during cell division. A Ruthenium Red screen for cellular adhesion mutants identified the family of 5 ELMO proteins that are critical for proper cellular adhesion. To further our understanding of plant cellular adhesion and pathways of pectin synthesis and modification, this work investigates ELMO5. Plants homozygous for a T-DNA insertion in ELMO5 and a new deletion mutant allele generated using CRSPR do not have a cellular adhesion phenotype, suggesting it is either not critical for cellular adhesion or is redundant with another gene. Redundancy within the ELMO family is identified through the analysis of double mutants of elmo5 and each of the other four elmo genes. Both elmo1-/- elmo5-/-and elmo4-/- elmo5-/-mutants have a visibly worse cellular adhesion defect phenotype, suggesting partial redundancy through the ELMO family. The mutants are also rescued by growth on agar, pointing to the importance of turgor pressure and osmotic potential in modulating cellular adhesion. Both ELMO4 and ELMO5 were found to localize to the Golgi using a GFP fusion, consistent with a role for ELMOs as scaffold for pectin biosynthesis.

- Restriction End Date: 2028-06-01
Date: 2023-01-01
Creator: Tabarak Al Musawi
Access: Access restricted to the Bowdoin Community

Date: 2014-05-01
Creator: Nicholas J Saba
Access: Access restricted to the Bowdoin Community