Fructose-bisphosphate aldolase (EC 4.1.2.13) is a key enzyme in glycolysis. We have characterized full-length coding sequences for aldolase genes from the cyst nematodes Heterodera glycines and Globodera rostochiensis, the first for any plant-parasitic nematode. Nucleotide homology is high (83% identity), and the respective sequences encode 40 kDa proteins with 89% amino acid identity. Genomic sequences contain six introns located at identical positions in both genes. Intron 4 in the H. glycines gene is >500 bp. Partial genomic sequences determined for seven other cyst nematode species reveal that the large fourth intron is characteristic of Heterodera but not Globodera aldolase genes. Total aldolase-like specific activity in homogenates from H. glycines was 2-fold lower than in either Caenorhabditis elegans or Panagrellus redivivus (P = 0.001). Activity in H. glycines samples was higher in juvenile stages than in adults (P = 0.003). Heterodera glycines aldolase has Km = 41 microM and is inhibited by treatment with carboxypeptidase A or sodium borohydride.
Keywords: Globodera; Heterodera; aldolase; cyst nematode; enzyme; gene; intron.