Phospholipases are key enzymes in pathogenic fungi that cleave host phospholipids, resulting in
membrane destabilization and host cell penetration. However, understanding the role of phospholipases
on the virulence of the filamentous fungus Purpureocillium lilacinum has been still rather limited. In this
study, pld gene was characterized. It encodes the protein phospholipase D (PLD) in P. lilacinum. This gene,
3303 bp open reading frame fragment (ORF), encodes a protein of 1100 amino acids with high similarity
to the same gene from Penicillium oxalicum and Aspergillus fumigatus. Secondary structure prediction
showed two PLD phosphodiesterase domains (437e464 bp and 885e912 bp). The pld gene was significantly
regulated during infection of Meloidogyne incognita eggs by P. lilacinum. The expression of pld
gene using RT-PCR was the highest at 36 and 48 h, which introduce evidence that the presence of
M. incognita may induce the expression of the pld gene in P. lilacinum. In addition, maltose and L-alanine
were found to increase the expression of pld gene. An acidic environment (pH 3.0e4.0) and moderate
temperatures (27e29
C) are favorable for pld expression in P. lilacinum.