Differential Expression Pattern of UGPase Gene Homologs ( StUGPase1 and StUGPase2 ) in Potato ( Solanum tuberosum L.) during Tuberization Process and Post-Harvest Storage Conditions

UDP-glucose pyrophosphorylase (UGPase) is one of the important key regulatory enzymes involved in sucrose and starch metabolism, and secondary cell wall synthesis during potato tuberization. It catalyzes the reversible formation of uridinediphosphate glucose (UDP-Glc) from glucose-1-phosphate (Glc-1-P) and uridine triphosphate (UTP). Although the enzyme is well characterized, the behavior of StUGPase homologs during changing metabolic flux at various tuber developmental stages of potato has poorly been understood. In the present study, the transcriptional behaviour of StUGPase homologs during different tuber development stages and post-harvest storage conditions was examined through real-time PCR. In silico analysis revealed the presence of two StUGPase homologs, StUGPase1 and StUGPase2. Both StUGPase1 and StUGPase2 were found to be expressed throughout the tuberization stages and storage. However , transcript abundance and cold-responsiveness StUGPase2 were found predominant. The findings indicate that StUGPase2 is the main StUGPase homolog involved in tuber development and cold responsiveness in potato. The information generated from the current experiment could speed up the potato improvement program for higher yield and better cold response under storage conditions.