Showing 1 - 10 of 12 Items
Date: 2015-05-01
Creator: Jaepil E Yoon
Access: Open access

Date: 2023-01-01
Creator: Nuoya (Laura) Yang
Access: Access restricted to the Bowdoin Community
Date: 2021-05-01
Creator: Bruce D. Kohorn, Frances D.H. Zorensky, Jacob Dexter-Meldrum, Salem Chabout, Gregory, Mouille, Susan Kohorn
Access: Open access
- Plant growth, morphogenesis and development involve cellular adhesion, a process dependent on the composition and structure of the extracellular matrix or cell wall. Pectin in the cell wall is thought to play an essential role in adhesion, and its modification and cleavage are suggested to be highly regulated so as to change adhesive properties. To increase our understanding of plant cell adhesion, a population of ethyl methanesulfonate-mutagenized Arabidopsis were screened for hypocotyl adhesion defects using the pectin binding dye Ruthenium Red that penetrates defective but not wild-type (WT) hypocotyl cell walls. Genomic sequencing was used to identify a mutant allele of ELMO1 which encodes a 20 kDa Golgi membrane protein that has no predicted enzymatic domains. ELMO1 colocalizes with several Golgi markers and elmo1-/- plants can be rescued by an ELMO1-GFP fusion. elmo1-/- exhibits reduced mannose content relative to WT but no other cell wall changes and can be rescued to WT phenotype by mutants in ESMERALDA1, which also suppresses other adhesion mutants. elmo1 describes a previously unidentified role for the ELMO1 protein in plant cell adhesion.
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.
Date: 2015-07-03
Creator: Bruce D. Kohorn
Access: Open access
- The Wall Associated Kinases (WAKs) bind to both cross-linked polymers of pectin in the plant cell wall, but have a higher affinity for smaller fragmented pectins that are generated upon pathogen attack or wounding. WAKs are required for cell expansion during normal seedling development and this involves pectin binding and a signal transduction pathway involving MPK3 and invertase induction. Alternatively WAKs bind pathogen generated pectin fragments to activate a distinct MPK6 dependent stress response. Evidence is provided for a model for how newly generated pectin fragments compete for longer pectins to alter the WAK dependent responses.

Date: 2013-05-01
Creator: Patrick J Lariviere
Access: Access restricted to the Bowdoin Community

Date: 2014-05-01
Creator: Divya Hoon
Access: Access restricted to the Bowdoin Community

Date: 2015-05-01
Creator: Joshua A Benton
Access: Access restricted to the Bowdoin Community

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

Date: 2016-01-01
Creator: Cody P Woods
Access: Access restricted to the Bowdoin Community