control of glucosylceramide production and morphogenesis by the bar1 ceramide synthase in fusarium graminearum葡糖神经酰胺的生产控制花药对赤霉病bar1神经酰胺合成酶的形态发生.pdfVIP

Control of Glucosylceramide Production and Morphogenesis by the Bar1 Ceramide Synthase in Fusarium graminearum William R. Rittenour1,3¤, Ming Chen2,3, Edgar B. Cahoon2,3, Steven D. Harris1,3* 1 Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America, 2 Department of Biochemistry, University of Nebraska- Lincoln, Lincoln, Nebraska, United States of America, 3 Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America Abstract The contribution of plasma membrane proteins to the virulence of plant pathogenic fungi is poorly understood. Accordingly, the objective of this study was to characterize the acyl-CoA dependent ceramide synthase Bar1 (previously implicated in plasma membrane organization) in the wheat pathogen Fusarium graminearum. The role of Bar1 in mediating cell membrane organization was confirmed as DBAR1 mutants failed to display a distinct sterol-rich domain at the hyphal tip. The DBAR1 mutants were non-pathogenic when inoculated onto wheat heads, and their in vitro growth also was severely perturbed. DBAR1 mutants were incapable of producing perithecia (sexual fruiting structures) and only produced macroconidia (asexual spores) in the presence of NaCl. Sphingolipid analyses indicated that Bar1 is specifically necessary for the production of glucosylceramides in both F. graminearum and Aspergillus nidulans. Interestingly, glucosylceramides appear to mediate sensitivity to heat stable antifungal factor (HSAF), as, in addition to DBAR1 mutants, a glucosylceramide synthase deficient mutant of Yarrowia lipolytica is also resistant to HSAF. Citation: Rittenour WR, Chen M, Cahoon EB, Harris SD (2011) Control of Glucosylceramide Production and Morphogenesis by the Bar1 Ceramide Synthase in Fusarium