|Puckhaber, Lorraine - TAMU|
|Krause, Melanie - USDA/ARS/SPARC|
Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: November 18, 1999
Publication Date: N/A
Technical Abstract: Plants synthesize low molecular weight toxic compounds when they are infected by pathogenic microorganisms. Such compounds are called phytoalexins. Kenaf (Hibiscus cannabinus), which is highly resistant to the plant pathogen Verticillium dahliae, produced the potent phytoalexin o-hibiscanone (3,8-dimethyl-1,2-naphthoquinone). Kenaf and cotton are both in the Malvaceae family. Utilizing molecular biology, it may be possible to alter the cotton phytoalexin biosynthetic pathway to increase resistance to plant pathogens. We wish to determine the critical relationships between the geometric and chemical characteristics that are required to maximize toxicity in this type of compound. To this end, we have assayed the toxicity of a group of substituted o- and p-quinones. Of the compounds tested only 6-methoxy-1,2-naphthoquinone had a toxicity equal to that of o-hibiscanone. 1,2-Naphthoquinone was about one half as toxic and 1,4-naphthoquinone was slightly less toxic. The toxicity of over fifteen related compounds is reported.