Fusarium graminearum is the causal agent of head blight
(scab) of wheat and barley, a plant disease with great impact on
U.S. agriculture and society during the past decade. Approximately
$3 billion were lost to U. S. agriculture during wheat scab
epidemics in the 1990s, resulting in devastating effects on farm
communities in the upper Midwest and elsewhere (McMullen et al.,
1997; Windels, 2000). Moreover, the disease is becoming a threat to
the world's food supply due to recent head blight outbreaks in
Asia, Canada, Europe and South America (Dubin et al., 1997). The
fungus also infects and causes disease on corn and rice (Webster
and Gunnell, 1992; White, 1999). The pathogen poses a two-fold
threat: first, infested cereals are significantly reduced in seed
quality and yield, and secondly, scabby grain is contaminated with
trichothecene and estrogenic mycotoxins, making it unsuitable for
food or feed (McMullen et al., 1997). As a food safety issue,
trichothecene toxins such as "vomitoxin" (deoxynivalenol) pose a
serious hazard to human and animal health because these
sesquiterpenoids are potent inhibitors of eukaryotic protein
biosynthesis. Vomitoxin causes weight loss and feeding refusal in
non-ruminant livestock, and human ingestion of grain contaminated
with F. graminearum has been associated with alimentary
toxic aleukia as well as illness characterized by nausea, vomiting,
anorexia, and convulsions (Murphy and Armstrong, 1995).
Trichothecenes also are powerful modulators of human immune
function and may promote neoplasms, cause autoimmune disease, or
have long-term effects on resistance to infectious disease by
altering immune response (Berek et al., 2001; Lindsay, 1997).
Sequenced strain information: The strain chosen for sequencing by
the International Gibberella zeae Genomics Consortium
(IGGR) was PH-1 (NRRL 31084). Fusarium graminearum is the
predominant FHB species causing scab of wheat and barley in North
America and Europe and is distributed worldwide (O'Donnell et al.,
2000, 2004). Isolated in Michigan, PH-1 is highly fertile (Trail
and Common, 2000), produces trichothecenes and zearalenone ,
sporulates abundantly in pure culture and is highly pathogenic to
wheat and barley. The strain can be readily transformed and is
closely related to strain GZ3639 (NRRL 29169) that has been studied
for trichothecene biosynthesis (Brown et al., 2001) and strain
00-676 (NRRL 34097) used as one parent with PH-1 for the genetic
map (Gale et al., 2005).