Nuclear Function of Subclass I Actin-Depolymerizing Factor Contributes to Susceptibility in XXXX to an Adapted Powdery Mildew Fungus.

@entity3785 @entity7214 @entity958 @entity273 @entity72694 @entity72693 @entity1786
Actin-depolymerizing factors (ADFs) are conserved proteins that function in regulating the structure and dynamics of actin microfilaments in eukaryotes. In this study, we present evidence that @entity958 ( @entity958 ) subclass I ADFs, particularly @entity72693 , functions as a susceptibility factor for an adapted powdery mildew fungus. The null mutant of @entity72693 significantly increased resistance against the adapted powdery mildew fungus Golovinomyces orontii. The degree of resistance was further enhanced in transgenic plants in which the expression of all subclass I ADFs (i.e. @entity72694 - @entity72693 ) was suppressed. Microscopic observations revealed that the enhanced resistance of @entity72693 and @entity72694 -4 knockdown plants ( @entity72694 -4Ri) was associated with the accumulation of @entity273 and cell death specific to G. orontii-infected cells. The increased resistance and accumulation of @entity273 in @entity72694 -4Ri were suppressed by the introduction of mutations in the @entity3785 - and @entity7214 -signaling pathways but not by a mutation in the @entity1786 -signaling pathway. Quantification by microscopic images detected an increase in the level of actin microfilament bundling in @entity72694 -4Ri but not in @entity72693 at early G. orontii infection time points. Interestingly, complementation analysis revealed that nuclear localization of @entity72693 was crucial for susceptibility to G. orontii. Based on its G. orontii-infected-cell-specific phenotype, we suggest that subclass I ADFs are susceptibility factors that function in a direct interaction between the host plant and the powdery mildew fungus.
