Changes in FaRP-like peptide levels during development of eggs from the plant-parasitic cyst nematode, Heterodera glycines.
The plant-parasitic cyst nematode Heterodera glycines requires a host plant to complete its life cycle, which involves hatching of infective juveniles that parasitize through root entry. A laboratory population of H. glycines grown on soybean, Glycine max, undergoes a sharp increase in maturity between 5 and 6 weeks in culture, as measured by the proportion of eggs containing well developed pre-hatch juveniles (late development eggs) versus eggs without visible juveniles (early development eggs). The median percent of eggs classified as late development, representing all samples taken from 4 to 7 weeks in culture, was 61%. For all samples taken up to 5 weeks, 80% scored below the median. In samples taken after 5 weeks, 15% scored below the median. This shift in population maturity was accompanied by a significant increase (P < 0.01) in the number of hatched juveniles present in each sample. There was also a significant increase (P < 0.02) in amount of FaRP-like peptide detected by specific ELISA. Total FaRP levels increased from 0.18 +/- 0.07 fMol FLRFamide equivalents per ng protein in early development eggs to 0.40 +/- 0.17 in late development eggs. The level remained high in hatched juveniles. HPLC/ELISA detected as many as nine potential FaRPs in H. glycines, two of which were specifically increased (P < 0.005) in hatched juveniles. The association of FaRPs with maturing eggs and the possible involvement of these neuropeptides with juvenile hatching and motility are discussed.
Masler
E P
EP
Nematology Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA. maslere@ba.ars.usda.gov
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019835:FMRFamide / Q000032:analysis* / Q000276:immunology; D005260:Female; D015801:Helminth Proteins / Q000032:analysis; D006790:Host-Parasite Interactions; D049990:Membrane Transport Modulators / Q000032:analysis*; D009348:Nematoda / Q000737:chemistry* / Q000196:embryology; D010063:Ovum / Q000737:chemistry; D010270:Parasite Egg Count; D013025:Glycine max / Q000469:parasitology*
D015801:Helminth Proteins; D049990:Membrane Transport Modulators; D019835:FMRFamide