The Role of a Zinc Finger-containing Glycine-rich RNA-binding Protein During the Cold Adaptation Process in Arabidopsis thaliana

The mechanistic role of a glycine-rich RNA-binding protein designated atRZ-1a that contributes to enhance cold tolerance in Arabidopsis was investigated. Overexpression of atRZ-1a did not affect the expression of various cold-responsive genes such as COR6.6, COR15a, COR47, RD29A, RD29B and LTI29. Proteome analyses revealed that overexpression of atRZ-1a modulated the expression of several stress-responsive genes, and the transcript levels and RNA stability of these target genes were not affected by atRZ-1a. atRZ-1a successfully complements the cold sensitivity of Escherichia coli lacking four cold shock proteins. These results strongly suggest that atRZ-1a plays a role as an RNA chaperone during the cold adaptation process.