关键词: 山桃, 低温胁迫, PdCIbHLH, 表达分析, 功能鉴定

Abstract: This study is aiming at cloning PdICbHLH from Prunus davidiana Franch，to analyze its expression pattern and reveal biological functions involved in cold stress. PdCIbHLH gene was obtained，and the open reading frame（ORF）contained 1 617 bp，encoding a protein of 539 amino acid residues. Sequence analysis indicated that PdCIbHLH exhibited the structures of bHLH domain. Phylogenetic relationship analysis showed that the homology of PdCIbHLH was close to the MdICE1. The qRT-PCR analysis indicated that PdCIbHLH was expressed in different organs. The expression showed high level in leaves，and the lowest in stems，and then expression of PdCIbHLH in leaves was induced by 4 ℃ treatment. The PdCIbHLH-overexpressing Arabidopsis exhibited increased tolerance to cold stress. Yeast one-hybrid assay showed that PdCIbHLH interacted with promoter of AtCBF3. The transient expression assays showed that PdCIbHLH could induce the expression of AtCBF3. It is speculated that PdCIbHLH was an important regulatory in response to cold treatment by directly activating the transcript of CBF.

Key words: Prunus davidiana, cold stress, PdCIbHLH, expression analysis, functional identification