Genome-wide identification and characterization of the bZIP gene family in Siberian apricot (Prunus sibirica) and their role under cold stress.

PsbZIP28 is significantly upregulated during the late stage of cold stress in Siberian apricot (Prunus sibirica) and its transient overexpression enhances cold tolerance in Populus ussuriensis.

• Why it matters: Forest-tree bZIP transcription factors are important for cold stress responses, but systematic characterization and mechanistic evidence in Prunus sibirica are lacking.
• What they did: The study identified 41 PsbZIPs across the P. sibirica genome (12 subfamilies), assessed conserved exon-intron and motif patterns, and used qRT-PCR to profile cold-stress expression; PsbZIP28 was tested by transient overexpression, nuclear localization, and yeast self-activation assays.
• The result: PsbZIP28 shows late-stage cold upregulation, localizes to the nucleus, and has C-terminus transcriptional activation activity, enabling mechanistic follow-up and supporting bZIP-based cold-tolerance breeding in woody plants.