Abstract:

Gene expression microarray of petunia was applied to select cold responsive genes，from which a C2H2-type zinc-finger protein gene PhZPT2-12 was discovered. Using inbred line‘H’as the template，PhZPT2-12 was isolated. It contains an Open Reading Frame（ORF）of 525 bp，encoding a peptide of 174 aa with two classical C2H2 domains. Phylogenetic tree analysis demonstrated that PhZPT2-12 is closely related to SlZF3 reported. Subcellular localization and transactivation activity assays showed that PhZPT2-12 was targeted to nucleus and owned no transcriptional activation activity. Semi-quantitative RT-PCR analysis revealed that the expression of PhZPT2-12 was higher in roots，stems and leaves，whereas much lower in mature flowers under normal growth conditions. Stress induced expression analysis showed that the expression of PhZPT2-12 could be induced by cold rapidly，also by salt and drought in different degrees. It is suggested that PhZPT2-12 is associated with the responses to cold，salt and other abiotic stresses.

Key words: petunia, cold stress, C2H2 zinc-finger protein, transcription factor, expression analysis