Title: Analysis of transporter responsible for the secretion of fusaric acid from the plant pathogen Fusarium oxysporum f. sp. vasinfectum Authors
Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2013
Publication Date: December 10, 2013
Citation: Crutcher, F.K., Liu, J., Bell, A.A., Stipanovic, R.D., Kenerely, C.M. 2013. Analysis of transporter responsible for the secretion of fusaric acid from the plant pathogen Fusarium oxysporum f. sp. vasinfectum. APS Annual Meeting. CDROM. Technical Abstract: Fusaric acid (FA), a phytotoxic polyketide produced by Fusarium oxysporum f. sp. vasinfectum (Fov), has been suggested to be associated with disease symptoms on cotton. In response to a potential threat on cotton production by the introduction of high FA producing strains from Australia, new sources for resistance are being pursued. A putative transporter (fubT), in close proximity to the cluster responsible for FA production, was sequenced in the Australian isolate 1089. Sequence analysis of fubT reveals a similarity to several members of the major facilitator superfamily (MFS) of integral membrane transporter proteins known to confer resistance to various antibiotics and toxins in fungi and bacteria. To explore its function in FA production and resistance, a targeted gene disruption of fubT was constructed. Deletion transformants were found to lack secretion of FA and have observable deficits in growth. Some secondary metabolite transporters from other fungi have a role in self-protection by maintaining low intracellular concentration of toxin. To assess if this transporter is involved in a form of self-protection to FA that can be translated into other organisms, fubT was transformed into the biocontrol fungus, Trichoderma virens Gv29-8. Understanding and identifying new forms of resistance for transgenic use provides novel resistance mechanisms that have the potential to control high FA producing Fov strains on cotton.