title: FUBT, a putative MFS transporter, promotes secretion of fusaric acid in the cotton pathogen Fusarium oxysporum f. sp. vasinfectum.
abstract: Fusaric acid (FA) is a key component in virulence and symptom development in cotton during infection by Fusarium oxysporum. A putative major facilitator superfamily (MFS) transporter gene was identified downstream of the polyketide synthase gene responsible for the biosynthesis of FA in a region previously believed to be unrelated to the known FA gene cluster. 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 potential secondary resistance mechanism, the production of FA derivatives, was observed in FUBT deletion mutants. Molecular analysis of key biochemical processes in the production of FA could lead to future host plant resistance to Fusarium pathogens.
authors: USDA-ARS, Southern Plains Agricultural Research Center, 2765 F&B Road, College Station, TX 77845, USA.
authors: Frankie K
authors: FK
authors: Crutcher
authors: USDA-ARS, Southern Plains Agricultural Research Center, 2765 F&B Road, College Station, TX 77845, USA jinggao.liu@ars.usda.gov.
authors: Jinggao
authors: J
authors: Liu
authors: USDA-ARS, Southern Plains Agricultural Research Center, 2765 F&B Road, College Station, TX 77845, USA.
authors: Lorraine S
authors: LS
authors: Puckhaber
authors: USDA-ARS, Southern Plains Agricultural Research Center, 2765 F&B Road, College Station, TX 77845, USA.
authors: Robert D
authors: RD
authors: Stipanovic
authors: USDA-ARS, Southern Plains Agricultural Research Center, 2765 F&B Road, College Station, TX 77845, USA.
authors: Alois A
authors: AA
authors: Bell
authors: Cotton Incorporated, 6399 Weston Parkway, Cary, NC 27513, USA.
authors: Robert L
authors: RL
authors: Nichols
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D005110:Extracellular Space / Q000378:metabolism; D005669:Fusaric Acid / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D003368:Gossypium / Q000382:microbiology*; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D005669:Fusaric Acid