Filters

2012 - 20182
Reset filters

Settings

Subject: Cercospora beticola.

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Characterization of Cytochrome B from European Field Isolates of Cercospora Beticola with Quinone Outside Inhibitor Resistance
    (North Dakota State University, 2012) Birla, Keshav
    Cercospora leaf spot (CLS), caused by the fungal pathogen Cercospora beticola, is the most important foliar disease of sugar beet worldwide. Control strategies for CLS rely heavily on fungicides including quinone outside inhibitor (QOI) fungicides. We collected 866 C. beticola isolates from sugar beet growing regions in France and Italy and assessed their sensitivity to the QOI fungicide pyraclostrobin. To gain an understanding of the molecular basis of QOI resistance, we cloned the full-length coding region of Cbcytb. All tested QOI-resistant isolates harbored a point mutation in Cbcytb at nucleotide position 428 that conferred an exchange from glycine to alanine at amino acid position 143 (G143A). A PCR assay was developed to discriminate QOI-sensitive and QOI-resistant isolates based on the G143A mutation. Our results indicate that QOI resistance has developed in some European C. beticola populations in Italy and monitoring the G143A mutation is an essential fungicide resistance management strategy.
  • No Thumbnail Available
    Item
    Expression Analysis of the Expanded Cercosporin Gene Cluster in Cercospora beticola
    (North Dakota State University, 2018) Stott, Karina
    Cercospora leaf spot is an economically devastating disease of sugar beet caused by the fungus Cercospora beticola. It has been demonstrated recently that the C. beticola CTB cluster is larger than previously recognized and includes novel genes involved in cercosporin biosynthesis and a partial duplication of the CTB cluster. Several genes in the C. nicotianae CTB cluster are known to be regulated by ‘feedback’ transcriptional inhibition. Expression analysis was conducted in wild type (WT) and CTB mutant backgrounds to determine if feedback inhibition occurs in C. beticola. My research showed that the transcription factor CTB8 which regulates the CTB cluster expression in C. nicotianae also regulates gene expression in the C. beticola CTB cluster. Expression analysis has shown that feedback inhibition occurs within some of the expanded CTB cluster genes. The partial duplication of the CTB cluster was not found to be light activated or subject to feedback inhibition.