Overexpression of SlCZFP1, a Novel TFIIIA-type Zinc Finger Protein from Tomato, Confers Enhanced Cold Tolerance in Transgenic Arabidopsis and Rice

Abstract

The C2H2-type (also called TFIIIA-type) zinc finger protein family is a major family of eukaryotic transcription factors. C2H2-type zinc finger proteins in plants play important roles in regulating various developmental processes or responses to abiotic stresses. We isolated a complementary deoxyribonucleic acid (cDNA) clone, designated Solanumlycopersicumcold zinc finger protein 1 (SlCZFP1), from tomato by analyzing the previous microarray data of the low-temperature transcriptome of tomato. SlCZFP1 encodes a novel TFIIIA-type zinc finger protein, which contains two typical zinc finger motifs, CX2–4 CX3FX3QALGGHX3–5H, and a potential nuclear localization signal (NLS). The SlCZFP1–GFP fusion protein was localized to the nucleus in a transient expression assay. Expression of SlCZFP1 was strongly induced by cold stress, dehydration, and salt treatment, but not by abscisic acid (ABA). Overexpression of SlCZFP1 in transgenic Arabidopsis and rice induced constitutive expression of cold-regulated (COR) or cold-responsive genes and conferred enhanced tolerance to freezing or cold treatments for non-acclimate transgenic plants, compared with wild-type plants. However, there was no obvious enhancement observed in drought and salt tolerance. Our data suggest that SlCZFP1 plays an important role in plant responses to cold stress by regulating cold-responsive gene expression and that SlCZEP1 might be a useful gene for improving cold tolerance in crop plants.