Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 5, 2003
Publication Date: January 5, 2003
Citation: Matthews, B.F., Tucker, M.L., Macdonald, M.H., Thai, V.K. 2003. Molecular characterization of arginine kinases in the soybean cyst nematode (heterodera glycines).. Journal of Nematology. 35:252-258. Interpretive Summary: Soybean cyst nematode (SCN) is the primary pathogen of soybean causing an estimated $700 million loss in production in 2002. Arginine kinases, enzymes important to energy metabolism in many invertebrates such as nematodes, were selected as potential targets for controlling SCN infections. Arginine kinases are not found in vertebrates, which includes mammals. We have identified multiple arginine kinases in SCN and characterized their expression patterns during successive stages of nematode development. In addition we have analyzed the hereditary relationship of the nematode arginine kinases with arginine kinases from insects and mollusks. Characterization of arginine kinases in nematodes may lead to improved mechanism for the control of SCN infection of soybean. Our data provide essential information and tools for other scientists and industrial partners to develop methods for enhancing nematode resistance in soybean and other crops.
Technical Abstract: Arginine kinase (AK) is a phosphagen kinase that plays a key role in energy mobilization in invertebrates. Alignment of ESTs in the public database for soybean cyst nematode (SCN; Heterodera glycines) produced two separate contiguous sequences (contigs) and three singletons encoding peptides with high similarity to AKs in the Swisspro database. One contig, Hg-AK1, had many more ESTs (244) in the alignment than the other four sequences; nonetheless, the consensus sequence for Hg-AK1 was missing much of the 5=A2 end. A clone for the 5=A2 end for Hg-AK1 was obtained and fully sequenced. The cDNA contained an open reading frame of 1080 nt encoding a protein of 360 amino acids, a predicted molecular weight of 40 kDa, and a predicted isoelectric point of 8.33. PCR primer pairs were successfully prepared for three different AKs and semi-quantitative RT-PCR used to determine their expression patterns at different stages of the SCN lifecycle. Hg-AK1 and Hg-AK3 were constitutively expressed at all stages of SCN development whereas Hg-AK2 was most abundant late in development at the adult stage. Phylogenetic analysis of contigs for several different nematode AKs indicates three separate groupings of nematode genes. Moreover, comparison of peptide sequences for near full-length nematode cotigs with other AKs in the Swisspro database indicates that the three groupings of nematode AKs evolved from a single gene after divergence of insects and nematodes.