Abstract
In response to cold, E. coli accumulates cold shock proteins (CSPs) that function as a RNA chaperone. Plant cold shock domain (CSD) proteins contain a CSD that is highly conserved with bacterial CSPs. A wheat CSD protein (WCSP1) has been characterized and shown to have RNA chaperone activity in our previous studies. Here, we performed functional characterization of one of the four Arabidopsis CSPs (AtCSP3). Nucleic acid binding assays revealed that AtCSP3 binds both ss and dsDNA. AtCSP3 expression was up-regulated in response to cold treatment at 4°C. Promoter-GUS analysis revealed tissue specific expression of AtCSP3 in anthers and shoots and root tips within the seedlings. AtCSP3 knockout mutant was less freezing tolerant than wild -type with or without cold-acclimation, while transgenic plants overexpressing AtCSP3 exhibited higher freezing tolerance than wild-type. These data suggested that AtCSP3 is required for basal and induced freezing tolerance during cold acclimation in Arabidopsis.
