Poster: Temperature Responses

Abs # 188: Pepper Microarray Data Reveal That Major Responses of Low Temperature Are Regulated to Protein Stability and Membrane Fluidity

Presenter:	Kim, Sihyun , argus2@hanafos.com
Authors	Kim, Sihyun  (A)   Baek, Ji-Seon  (A)   Lim, Jiyoun  (A)   Lee, Kwang-Woong  (A)
Affiliations:	(A): School of Biological Sciences, Seoul National University,

Plants response to changes in low temperature by regulating expression of a set of genes which is related to environmental stresses. Our study with cDNA microarray demonstrates that major responses of low temperature are the regulation on protein stability and membrane fluidity in pepper (Capsicum annuum L.). We isolated differentially expressed cold-elevated or cold- repressed genes among 2,500 genes in hot pepper. As a result, 1,652 cDNAs for cold-inducible genes were isolated, and among them 250 were found to be independent cold-inducible. Fifty five genes were also identified as unknown function, but related to the low temperature stress. The data were divided into 8 classes such as cold-repressed, cell cycle regulation, protein degradation, metabolism, transcription factor, transport, signal transduction, and unknown genes. The results were clustered using K means method. Representative data were confirmed by northern blot analysis on stress conditions. Among them, 39% is related to protein synthesis and stability, and 27% to membrane fluidity. These results are similar to cold response mechanism of cyanobacteria. Therefore we came to conclusion that plant and cyanobacteria have the same defense mechanism to low temperature stress.