title: Cold shock domain protein 3 regulates freezing tolerance in Arabidopsis thaliana.
abstract: In response to cold, Escherichia coli produces cold shock proteins (CSPs) that have essential roles in cold adaptation as RNA chaperones. Here, we demonstrate that Arabidopsis cold shock domain protein 3 (AtCSP3), which shares a cold shock domain with bacterial CSPs, is involved in the acquisition of freezing tolerance in plants. AtCSP3 complemented a cold-sensitive phenotype of the E. coli CSP quadruple mutant and displayed nucleic acid duplex melting activity, suggesting that AtCSP3 also functions as an RNA chaperone. Promoter-GUS transgenic plants revealed tissue-specific expression of AtCSP3 in shoot and root apical regions. When exposed to low temperature, GUS activity was extensively induced in a broader region of the roots. In transgenic plants expressing an AtCSP3-GFP fusion, GFP signals were detected in both the nucleus and cytoplasm. An AtCSP3 knock-out mutant (atcsp3-2) was sensitive to freezing compared with wild-type plants under non-acclimated and cold-acclimated conditions, whereas expression of C-repeat-binding factors and their downstream genes during cold acclimation was not altered in the atcsp3-2 mutant. Overexpression of AtCSP3 in transgenic plants conferred enhanced freezing tolerance over wild-type plants. Together, the data demonstrated an essential role of RNA chaperones for cold adaptation in higher plants.
authors: Crop Cold Tolerance Research Team, National Agricultural Research Center for Hokkaido Region, Hitsujigaoka 1, Toyohira-ku, Sapporo 062-8555, Japan.
authors: Myung-Hee
authors: MH
authors: Kim
authors: Kentaro
authors: K
authors: Sasaki
authors: Ryozo
authors: R
authors: Imai
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D005615:Freezing; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; C544303:CSP3 protein, Arabidopsis; D006360:Heat-Shock Proteins