2007 Volume 1 Pages 46-56
Plant associated endophytic Acremonium species are capable of interacting with the host plant and altering its response towards pathogens and pests. Specialized root-colonizing Acremonium spp. can achieve biocontrol effects based on induced disease resistance in whole plant assays. However, these fungi are hard to detect and to study in root tissue by classical methods of light microscopy or microbiology. To enable further progress in investigations of induced mechanisms of defence in the plant, better visualization of the endophytic symbiont Acremonium strictum was attempted by use of autofluorescent GFP-transformants. Subcultures of three stable transformed A. strictum-isolates were used in agar plate assays with sterilized flax seedlings to document root colonization and infection with confocal laser scanning microscopy. In greenhouse tests the fitness of the transformants was proved in comparison to the wild type A. strictum for bioprotection against Fusarium-wilt. In these trials the endophyte trait to reduce disease incidence and symptom severity was verified in all three transformants as well as in the wild type of A. strictum. The suitability of these transformants for further research scopes and microscopy methods are indicated.
