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.
Nematology Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA. maslere@ba.ars.usda.gov
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Masler
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