Involvement of a putative response regulator FgRrg-1 in osmotic stress response, fungicide resistance and virulence in Fusarium graminearum. Academic Article uri icon

abstract

  • Response regulator (RR) proteins are core elements of the high-osmolarity glycerol (HOG) pathway, which plays an important role in the adaptation of fungi to a variety of environmental stresses. In this study, we constructed deletion mutants of two putative RR genes, FgRRG-1 and FgRRG-2, which are orthologues of Neurospora crassa RRG-1 and RRG-2, respectively. The FgRRG-1 deletion mutant (FgRrg1-6) showed increased sensitivity to osmotic stress mediated by NaCl, KCl, sorbitol or glucose, and to metal cations Li(+) , Ca(2+) and Mg(2+) . The mutant, however, was more resistant than the parent isolate to dicarboximide and phenylpyrrole fungicides. Inoculation tests showed that the mutant exhibited decreased virulence on wheat heads. Quantitative real-time polymerase chain reaction assays indicated that the expression of FgOS-2, the putative downstream gene of FgRRG-1, was decreased significantly in FgRrg1-6. All of the defects were restored by genetic complementation of FgRrg1-6 with the wild-type FgRRG-1 gene. Different from the FgRRG-1 deletion mutant, FgRRG-2 deletion mutants were morphologically indistinguishable from the wild-type progenitor in virulence and in sensitivity to the dicarboximide fungicide iprodione and osmotic stresses. These results indicate that the RR FgRrg-1 of F. graminearum is involved in the osmotic stress response, pathogenicity and sensitivity to dicarboximide and phenylpyrrole fungicides and metal cations.

published proceedings

  • Mol Plant Pathol

author list (cited authors)

  • Jiang, J., Yun, Y., Fu, J., Shim, W., & Ma, Z.

citation count

  • 25

complete list of authors

  • Jiang, Jinhua||Yun, Yingzi||Fu, Jing||Shim, Won-Bo||Ma, Zhonghua

publication date

  • June 2011

publisher