Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2007
Publication Date: 7/1/2007
Citation: Replogle, A., Wang, J., Wang, X., Davis, E.L., Mitchum, M.G. 2007. Phenotypic characterization of roots responding to Heterodera glycines CLE peptides. Phytopathology. 97:S98
Technical Abstract: Parasitism genes coding for secreted CLAVATA3/ESR(CLE)-like peptides are expressed in the dorsal gland cell of the soybean cyst nematode (SCN), Heterodera glycines, during syncytium induction and maintenance. Recent data indicate that there are two predominant forms of SCN CLEs, HgCLEA and HgCLEB, that only differ in a variable domain immediately upstream of the conserved CLE domain. When overexpressed in Arabidopsis, HgCLEA and not HgCLEB results in shoot and floral meristem defects, the severity of which correlates with expression level of the transgene. Roots of overexpression lines exhibit premature termination of the primary root meristem. Similarly, when HgCLEs are overexpressed in soybean roots a range of growth rate phenotypes is observed. Exogenous application of a synthetic peptide corresponding to the CLE motif of HgCLE to Arabidopsis and soybean roots causes a short root phenotype similar to synthetic plant CLE peptide treatment and overexpression lines. To assess the changes that are occurring in the root on a cellular level, cell identity marker lines treated with nematode CLE peptides are being monitored using confocal microscopy. These studies provide evidence of a role for HgCLEs in ligand mimicry of plant signaling peptides to developmentally reprogram the fate of a particular cell or set of cells for syncytium development.