Previous Arabidopsis thaliana studies have found that salicylic acid (SA) is
the hormone that triggers the plant defense response against biotrophic and
hemi-biotrophic pathogens as well as limit nematode reproduction. On the
other hand, jasmonic acid (JA) is critical to defense response against
necrotrophic pathogens. This knowledge derived from Arabidopsis studies were
translated to soybean.

Several Arabidopsis genes coding for components of SA and JA synthesis and
signaling in conferring resistance to soybean cyst nematode (SCN: Heterodera
glycines) were tested. Three overexpressed Arabidoposis genes in transgenic
soybean roots decreased the number of cysts formed by SCN to less than 50%
compared to control roots. These three genes were AtNPR1, AtTGA2 and AtPR-5.
Another three Arabidopsis genes decreased the number of SCN cysts by at
least 40%, namely, AtACBP3, AtACD2 and AtCM-3. Meanwhile, overexpression of
another Arabidopsis gene, AtDND1, greatly increased susceptibility to SCN.

Knowledge of the pathogen defense system gained from studies of Arabidopsis
can be directly translated to soybean through direct overexpression of these
genes. This demonstrates functional compatibility of Arabidopsis genes with
soybean and may be used to engineer resistance to nematodes.

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