|Stipanovic, Robert - Bob|
|Bell, Alois - Al|
|Nichols, Robert - COTTON, INC.|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2014
Publication Date: 1/6/2015
Citation: Crutcher, F.K., Liu, J., Puckhaber, L.S., Stipanovic, R.D., Bell, A.A., Nichols, R.L. 2015. FUBT, a putative MFS transporter, promotes secretion of fusaric acid in the cotton pathogen Fusarium oxysporum f.sp. vasinfectum [abstract]. In: Proceedings of the Beltwide Cotton Conferences, January 5-7, 2015, San Antonio, Texas. 2015 CDROM.
Technical Abstract: Fusaric acid (FA), a phytotoxic polyketide produced by Fusarium oxysporum f. sp. vasinfectum (FOV), has been shown to be associated with disease symptoms on cotton. A gene located upstream of the polyketide synthase gene responsible for the biosynthesis of FA is predicted to encode a member of the major facilitator superfamily (MFS) of integral membrane transporter proteins known to confer resistance to various antibiotics and toxins in fungi and bacteria. Disruption of the transporter gene, designated FUBT, resulted in loss of FA secretion, decrease in FA production, and a decrease in resistance to high concentrations of FA. Uptake of exogenous FA was unaffected in the disruption transformants, suggesting that FA enters the cell in Fusarium by an independent mechanism. Thus, FUBT is involved both in the extracellular transport of FA and in resistance of F. oxysporum to this non-specific toxin. A hypothetical secondary resistance mechanism, the conversion of FA to fusarinolic acid (HOFA), was observed in FUBT deletion mutants. Molecular analysis of key biochemical processes in the production of FA may lead to future resistance to this economically important plant pathogen.