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.

SUBMITTER: Kim MH 

PROVIDER: S-EPMC2749119 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature