Polyamine Biosynthesis Regulated by StARD Expression Plays an Important Role in Potato Wound Periderm Formation

An acireductone dioxygenase (ARD) gene of potatoes was isolated from the expressed sequence tags (ESTs) of potato post-suberization cDNA libraries. The highest expression levels of the StARD gene and the protein appeared 36 h after suberization. An approximate 9-fold increase in ARD activity was detected at 36 h after wounding. Real-time reverse transcription-PCR (RT-PCR) analysis and immunolocalization studies revealed that StARD transcripts increase at the wound surface of potato tubers. The polyamine (PA) contents increased significantly after wounding at the wound surface. The increased PA content and ARD activity may play an important role in wound periderm formation.