Cloning and Expression Analysis on PmPGK1 and PmGPIC Genes in Pinus massoniana

Abstract:

To understand the functions of phosphoglycerate kinase 1 (PGK1) and cytosolic glucose phosphate isomerase (CPIC) of Pinus massoniana, the cDNA of PmPGK1 and PmGPIC were cloned by RACE, and the bioinformatic and subcellular localization of PmPGK1 and PmGPIC were analyzed, and then their expression patterns were performed by qRT-PCR. The results showed that the full-length cDNA of PmPGK1 and PmGPIC were 2 106 and 1 848 bp, encoding 507 and 566 amino acids, respectively. PmPGK1 and PmGPIC proteins were located in chloroplast and cytosol, respectively. The expression of PmPGK1 was in order of new leaf > old leaf > new stem > root > flower, while that of PmGPIC was old leaf > flower > new leaf > new stem > root. Under low temperature stress for 24 hours, the expression of PmPGK1 and PmGPIC decreased at first and then increased, and the expression of PmGPIC decreased to a low level after 2 hours. Under high CO₂ stress for 24 hours, the expression of PmPGK1 was significantly down-regulated, showing a trend of decrease-increase-decrease, while the down-regulation of PmGPIC was not obvious. Therefore, it was suggested that PmPGK1 mainly participated in the Calvin cycle and chloroplast/plast glycolysis, and PmGPIC was mainly involved in cytosolic glycolysis. The activities of PmPGK1 and PmGPIC were inhibited under low temperature stress, and PmPGK1 activity was significantly inhibited under high CO₂ stress, while PmGPIC activity was less affected.