|Overall, Christopher - GEORGE MASON UNIVERSITY|
|Aklharouf, Nadime - TOWSON UNIVERSITY|
Submitted to: Planta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 16, 2007
Publication Date: June 16, 2007
Citation: Klink, V.P., Overall, C.C., Aklharouf, N.W., Macdonald, M.H., Matthews, B.F. 2007. Laser capture microdissection (LCM) and comparative microarray expression analysis of syncytial cells isolated from incompatible and compatible soybean roots infected by soybean cyst nematode (Heterodera glycines). Planta. 226:1389-1409. Interpretive Summary: The soybean cyst nematode (SCN) is the major pest of soybean and causes hundreds of millions of dollars in losses each year in the U.S. The nematode feeds on soybean root cells. We compared gene expression patterns in soybean root cells being fed upon by SCN in both SCN-resistant and susceptible soybean to determine if we could identify genes that are highly expressed in resistant root cells and not highly expressed in susceptible cells. These genes may provide clues as to how soybean cells can be resistant to SCN. We identified several genes that were highly expressed in SCN-resistant compared to susceptible soybean root cells using sophisticated molecular biology techniques. These data will be useful to scientists developing new approaches to broadening resistance of soybean to SCN.
Technical Abstract: Syncytial cells in soybean (Glycine max cultivar [cv.] Peking) roots infected by incompatible (I) and compatible (C) populations of soybean cyst nematode [SCN] (Heterodera glycines) were collected using laser capture microdissection. Gene transcript abundance was assayed using an Affymetrix® soybean GeneChip® containing 37,744 probe sets. Our analyses identified differentially expressed genes in syncytial cells microdissected from roots undergoing I and C reactions. Our results show that the mass of transcriptional activity occurring in the whole root is obscuring identification of transcriptional events occurring within syncytial cells. In syncytial cells from I roots at three days post infection (dpi), genes encoding lipoxygenase, heat shock protein 70, and superoxidase dismutase were elevated almost 10-fold or more, while genes encoding several transcription factors and DNA binding proteins were also elevated, albeit at lower levels. In syncytial cells formed during the C interaction at three dpi, genes encoding prohibitin, the epsilon chain of ATP synthase, allene oxide cyclase and annexin were highly expressed. By eight days, several genes of unknown function and genes encoding a germin-like protein, peroxidase, lipoxygenase, GAPDH, 3-deoxy-D-arabino-heptolosonate 7-phosphate synthase, ATP synthase and a thioesterase were highly expressed. These observations demonstrate that gene expression is different in syncytial cells as compared to whole roots infected with nematodes. Our observations also show that gene expression is different between syncytial cells that were isolated from I and C roots and that gene expression is changing over the course of syncytial cell development as it matures into a functional feeding site.