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ARS Home » Research » Publications at this Location » Publication #92245
Title: DETECTION OF A CASCADE OF DIFFERENTIALLY EXPRESSED GENES

Author
item HEINZ, RUTH
item Macdonald, Margaret
item Matthews, Benjamin - Ben

Submitted to: Molecular Plant Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The soybean cyst nematode (SCN) is a devastating pest of soybean and can reduce soybean yield dramatically. SCN causes root degeneration, yellowing of the leaves and suppresses shoot growth. We used a new technique called differential display to determine which genes are expressed specifically in a resistant soybean cultivar as compared to a susceptible soybean cultivar upon SCN infection. We identified more than fifty genes that are turned on in the resistant cultivar that are not turned on in the sensitive cultivar. We detected genes that are induced at an early stage of the infection process that may signal other genes involved in plant defense that the nematode has invaded the soybean root. This information is useful to molecular biologists who want to know what genes are important to stop SCN from invading soybean and to geneticists who are interested in creating new soybean cultivars with resistance to SCN.

Technical Abstract: The soybean cyst nematode (SCN), Heterodera glycines Ichinoe is a devastating pest of the soybean, Glycine max L Merr, causing root necrosis, chlorosis and suppressing shoot growth. We used differential display to study gene expression in a resistant soybean cultivar compared to susceptible and uninoculated plants. Gene expression was monitored at 6, 12, 24, 48, 96 and 144 hours after nematode inoculation. We detected and isolated 51 unique DNA fragments corresponding to mRNA that were specifically induced in leaves or roots of resistant inoculated plants. The DNA fragment sequences were compared against nucleotide and protein databases to identify putative gene function. We detected genes that are induced at an early stage of the infection process, involving genes codifying for transcription factors, nucleotide binding proteins, protein kinases and leucine-rich repeats. These genes are induced during nematode penetration and migration through the root. We also identified genes involved in general defense response, induced at a later stage, coinciding with the degeneration of the nematode feeding site. This information is useful to molecular biologists interested in designing new resistance to SCN.