Shifts in banana root exudate profiles after colonization with the non-pathogenic Fusarium oxysporum strain Fo162.
The non-pathogenic fungus Fusorium oxysporum strain Fo162 can efficiently colonize banana roots and reduce infecting by the burrowing nematode Radopholus similis. It is assumed that the fungus triggers a systemic reaction in the plant, which is affecting the biochemical composition of the root exudates and is thus causing the reduction in nematode colonization. To characterize these shifts, a continuous flow experiment was set up to collect root metabolites on a matrix (XAD-4). Based on HPLC analysis, the extracts, collected from the XAD-4, showed no differences in the composition of the root exudates between plants colonized by the endophyte and the controls. However, the accumulation of several compounds differed significantly. When these extracts were used in a bioassay with Radopholus similis none of the sample-treatment combinations had a significant attracting or repelling effect on the nematodes. This experiment shows that non-pathogenic Fusarium oxysporum strain Fo162 is able to upregulate the synthesis of at least some, so far unidentified compounds released by banana roots under hydroponic conditions. Further studies and optimization of the experimental setup are required to determine whether or not increase in metabolite concentration can affect nematode responses in vitro and ultimately in vivo.
Kurtz
Andreas
A
Soil Ecosystem Phytopathology and Nematology, INRES-Plant Health Department, University of Bonn, Nussallee 9, DE-53115 Bonn, Germany.
Schouten
Alexander
A
D000975:Antioxidants / Q000494:pharmacology; D002109:Caffeic Acids / Q000494:pharmacology; D003373:Coumaric Acids / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005670:Fusarium / Q000502:physiology*; D018527:Hydroponics / Q000379:methods; D028521:Musa / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D046509:Tissue Culture Techniques
D000975:Antioxidants; D002109:Caffeic Acids; D003373:Coumaric Acids; D016166:Free Radical Scavengers; C004999:ferulic acid; C040048:caffeic acid; D004298:Dopamine