Nematology (2009) 11, 555-563

Modika R. Perera, Sharyn P. Taylor, Vivien A. Vanstone and Michael G.K. Jones (2009)
Protein biomarkers to distinguish oat and lucerne races of the stem nematode, Ditylenchus dipsaci, with quarantine significance for Western Australia
Nematology 11 (4), 555-563
Abstract: The stem and bulb nematode, Ditylenchus dipsaci, is a serious pest of forage, horticultural and other crops. The two races of D. dipsaci that occur in Australia are the oat and lucerne races. These two races have the 'normal' morphology compared to the 'giant' type that attacks Vicia faba. The oat and lucerne races have been found in eastern Australia but not in Western Australia. There are no morphological or specific molecular tests to differentiate races within closely related 'normal' types of D. dipsaci. The aim of this work was to find protein biomarkers that would differentiate oat and lucerne races of D. dipsaci using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS), 2-D PAGE and associated proteomics techniques. Three protein biomarkers at m/z 4313 ± 0.1%, 6300 ± 0.1% and 7460 ± 0.1% were found that discriminate the oat and lucerne races of D. dipsaci using MALDI-TOFMS. The biomarker at m/z 4313 ± 0.1% was the prominent race-specific marker for the lucerne race and is almost absent in the oat race. In addition, proteomic maps were obtained by 2-D PAGE of proteins extracted from oat and lucerne races of D. dipsaci. This analysis allowed a comparison of acetone soluble proteins of oat and lucerne races of D. dipsaci. A prominent protein spot was identified with an isoelectric point (pI) of about 5 and molecular mass ca 4.5 kDa for the lucerne race, which was absent in the oat race. This particular protein was trypsin-digested and analysed by MALDI-TOFMS and MALDI-TOF-TOFMS. The resultant spectra of peptide mass fingerprints (PMF) showed two major peptides at m/z 845 ± 0.1%, 916 ± 0.1% and a less intense peptide at m/z 1258 ± 0.1%. De novo sequencing and MS/MS interpreted amino acid sequences are presented.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Modika R. Perera, Vivien A. Vanstone, Michael G.K. Jones

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ditylenchus dipsaci	Alfalfa/lucerne (Medicago sativa)	Australia (South+SE)
	Ditylenchus dipsaci	Oat (Avena sativa)	Australia (South+SE)