Semester

Spring

Date of Graduation

2008

Document Type

Thesis

Degree Type

MS

College

Eberly College of Arts and Sciences

Department

Applied and Environmental Biology

Committee Chair

Dale Thomas Karlson

Abstract

Cold shock domain proteins, or CSPs, are among the most ancient and conserved nucleic acid binding proteins. They have been well characterized in prokaryotic systems but little is known about their function in plants. The overall objective of this study was to understand the evolution and function of the cold shock domain in plant model systems. To pinpoint conserved areas within CSD an alignment was made of the cold shock domain protein sequences based on nucleotide sequence information found within EST databases. A description of domains found in the plant CSPs was prepared and a descriptive nomenclature system was developed. The alignment was also used to analyze the phylogeny of CSPs by making a neighbor-joining tree and a maximum likelihood tree. Prediction software was used to predict sub-cellular localization and post-translation modifications by phosphorylation and sumoylation. To characterize the CSPs on a functional level, their expression in the cold response pathways of ICE1, CBF 1, 2, and 3, and ABA were analyzed by qRT-PCR. The characteristics of nucleic acid binding, cold induction, and localization of the CSPs in bryophytes, the earliest land plants, were also determined. Physcomitrella patens CSPs are capable of binding to nucleic acids and are cold inducible. Expression lines for two CSPs from Physcomitrella patens were created in order to view sub-cellular and tissue specific localization patterns over the course of the moss life cycle. It is hoped that this foundation of knowledge of the cold shock domain will lead to a better understanding of its functional importance in higher plants of agronomic importance.

Download

Share

COinS