Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/7/2002
Publication Date: N/A
Technical Abstract: Deoxynivalenol (DON) is a strong inhibitor of protein synthesis and also induces programmed cell death (PCD) in animal cells. DON is known to be toxic to plant cells, but the processes leading to cell death have been little investigated. In studying the effects of DON in detached leaves of barley, we obtained results that support the hypothesis that DON induces PCD: 1) DON induced a gradual dissolution of chloroplasts (with concomitant loss of carotenoid and chlorophyll pigments) extending over 3 to 5 days before cells collapsed. Mitochondria likewise became degenerate. The tissues also suffered significant electrolyte loss over the 3-5 day period. Thus, cells underwent an ordered sequence of autolytic events leading to death, typical of PCD. 2) Like DON, cycloheximide and chloramphenicol induced gradual loss of chloroplast pigmentation and of electrolytes. 3) CA++ ions, known to be essential for PCD in plant cells (Groover and Jones, 1999), markedly accelerated DON-induced loss of both chloroplast pigments and electrolytes from leaf tissues. Together, these results indicate that DON induces PCD in leaf tissues and, therefore, may do likewise in FHB-infected spike tissues.