Phospholipase Dα from Chorispora bungeana: cloning and partial functional characterization

Chorispora bungeana Fisch. and C.A. Mey (C. bungeana) is a rare alpine subnival plant species that is highly tolerant to environmental stress. Phospholipase D (PLD) is a key enzyme involved in membrane phospholipid catabolism during plant growth, development and stress responses. We have isolated and partially characterized a full-length cDNA encoding PLD alpha from the plantlets in vitro of C. bungeana, with the aim of furthering our understanding of the role of PLD alpha at the molecular level. The C. bungeana PLD alpha (CbPLD alpha) was found to encode a 810-amino acid protein with moderate to high nucleotide sequence similarity to previously reported plant PLD alpha genes. RT-PCR analyses suggested that CbPLD alpha gene expression is correlated with the CbPLD alpha activity when C. bungeana plantlets were treated with low temperature (4, 0 and -4 A degrees C). Furthermore, the CbPLD alpha gene was found to be expressed at high levels in leaf and root tissues. These results indicate that the CbPLD alpha may play an important role in response to low temperature stresses in C. bungeana.