| Summary: | <i>Verticillium dahliae</i> (<i>V. dahliae</i>) infects roots and colonizes the vascular vessels of host plants, significantly reducing the economic yield of cotton and other crops. In this study, the protein VdTHI20, which is involved in the thiamine biosynthesis pathway, was characterized by knocking out the corresponding <i>VdTHI20</i> gene in <i>V. dahliae</i> via <i>Agrobacterium tumefaciens</i>-mediated transformation (ATMT). The deletion of <i>VdTHI20</i> resulted in several phenotypic defects in vegetative growth and conidiation and in impaired virulence in tobacco seedlings. We show that VdTHI20 increases the tolerance of <i>V. dahliae</i> to UV damage. The impaired vegetative growth of <i>ΔVdTHI20</i> mutant strains was restored by complementation with a functional copy of the <i>VdTHI20</i> gene or by supplementation with additional thiamine. Furthermore, the root infection and colonization of the <i>ΔVdTHI20</i> mutant strains were suppressed, as indicated by green fluorescent protein (GFP)-labelling under microscope observation. When the RNAi constructs of <i>VdTHI20</i> were used to transform <i>Nicotiana benthamiana</i>, the transgenic lines expressing dsVdTHI20 showed elevated resistance to <i>V. dahliae</i>. Together, these results suggest that VdTHI20 plays a significant role in the pathogenicity of <i>V. dahliae</i>. In addition, the pathogenesis-related gene <i>VdTHI20</i> exhibits potential for controlling <i>V. dahliae</i> in important crops.
|
|---|
