Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/1998
Publication Date: N/A
Technical Abstract: Recent evidence shows that the oligosaccharides raffinose, stachyose and verbascose are intermediates in cell wall synthesis. Within sugarbeet (Beta vulgaris) tap roots, tissues immediately surrounding disease lesions caused by Rhizoctonia solani AG 2-2 accumulate phenolic compounds as part of a defense response, and lesion development is arrested at cool temperatures (15 degrees C). Experiments were done to determine if accumulation of oligosaccharides, indicative of new cell wall synthesis, also occurs in sugar beets in these tissues. The tissue immediately subtending arrested disease lesions contained concentrations of the oligosaccharides at least twice those of other tissues in the same roots, or of corresponding tissues from healthy roots. This finding indicates that renewed cell wall synthesis involving these compounds is a part of the defense response. This is the first report of accumulation of these oligosaccharides as part of a plant defense response; their involvement in disease resistance may be more widespread.