Role of the COP9 Signalosome In Defense Responses In tomato

<p>The COP9 Signalosome (CSN) is an evolutionarily conserved multi-protein complex that regulates proteasome-mediated proteolysis. While the CSN has been shown to function in various growth and developmental processes, the involvement of the CSN in the regulation of defense responses is largely unknown. It was shown that silencing of the CSN subunit <em>CSN5</em> resulted in reduced wound-and herbivory-induced levels of jasmonic acid and reduced expression of wound-response genes. Unexpectedly, these plants also showed increased pathogenesis-related gene expression. Consequently, <em>CSN5</em>&ndash;silenced plants were more susceptible to feeding by herbivorous insects and infection by a necrotrophic fungus.</p> <p>It has been shown previously in our lab that a MAP kinase signaling cascade is an essential part of systemin-mediated defense signaling and functions upstream of jasmonic acid biosynthesis. Co-silencing of <em>MPK1/2</em> and <em>CSN5</em> had a synergistic effect on pathogenesis-related gene expression, suggesting that they function in the same signaling network. Together these finding suggest a role for the CSN in regulating jasmonic acid-dependent plant defense responses.</p>

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Campus Access Dissertation

Discipline thesis:degree_discipline

Biological Sciences

Year

2010

Author dc:creator

• Hind, Sarah Refi

Contributors dc:contributor

• Johannes W. Stratmann

• Life Sciences
• Medicine and Health Sciences
• Physical Sciences and Mathematics
• COP9 Signalosome
• CSN
• Defense Responses
• MAPK

Statement dc:rights

• © 2010, Sarah Refi Hind

Repository record dc:identifier

https://scholarcommons.sc.edu/etd/187

OAI identifier oai:identifier

oai:scholarcommons.sc.edu:etd-1188