Citation:
Marin P, Jurado M, Magan N, Vazquez C, Gonzalez-Jaen MT, Effect of solute stress and temperature on growth rate and TRI5 gene expression using real time RT-PCR in Fusarium graminearum from Spanish wheat, International Journal of Food Microbiology, Volume 140, Issue 2-3, 2010, Pages 169-174.
Abstract:
The objective of this work was to study the effect of ecophysiological factors
on trichothecene gene expression and growth in Fusarium graminearum. The effect
of non-ionic solute water potentials and temperature was examined on in vitro
mycelial growth rates and on expression of the TRI5 gene, involved in
trichothecene biosynthesis, quantified by real time RT-PCR. This study showed
optimal values of 25 degrees C and -2.8 MPa (0.982 a(w)) for growth. Marginal
temperatures such as 15 degrees C and 30-35 degrees C, particularly in
combination with water potentials below -2.8 MPa, drastically reduced growth.
The expression of TRI5 was reasonably constant although some induction was
observed between 20 and 30 degrees C, the most favourable temperatures for
growth, depending on the water potential imposed, particularly at -7.0 MPa. A
temporal kinetic experiment at 25 degrees C examined the effect of ionic solute
stress on TRI5 gene expression and growth rate. The results indicated
independence of growth rate and TRIS expression, as the fungal biomass increased
with time while the gene expression remained constant. This suggested that
favourable conditions for growth will result in higher trichothecene production,
and that toxin production would always accompany the colonization process at a
steady rate while the conditions for growth are permissive. Quantification of
key biosynthetic toxin genes by real time RT-PCR was shown to be a valuable tool
to gain knowledge of the ecophysiological basis for trichothecene biosynthesis
and enable better control strategies to be developed during the life cycle of
this important mycotoxigenic pathogen of cereals. (C) 2010 Elsevier B.V. All
rights reserved.
