Exploring Sclerotinia sclerotiorum-resistance mechanisms in wild Brassica species and Arabidopsis, and their potential use in the practice


 

Team: Yan Zhao, Wanzhi Ye, Steffen Rietz
Supported by the Chinese Scholarship Council (CSC), 2015-2019   

Objectives:
Comparative RNAseq analysis identified a subset of genes, whose expression levels clearly associate with the resistance observed in Brassica wild species, providing first insights in the underlying Sclerotinia resistance mechanisms.

In support of this, we identified three Arabidopsis mutants with significantly increased resistance to Sclerotinia infection by screening of an activation-tagging Arabidopsis mutant collection with 50.000 lines.

 

Meanwhile, the targeted/activated genes have been identified, but the nature of the resulting resistance remains to be investigated. Unexpectedly, an at least one week early-bolting/flowering phenotype was observed by all three independent resistant mutants as compared with the wild type, thus raising the hypothesis that the activated resistance mechanism influences the bolting/flowering signal networks.

 

MicroRNAs (miRNAs) have emerged as central regulators of plant flowering time as well as of plant immunity. For instance, miR156 and miR172 proved to participate in the regulation of stress dependent change in flowering time.

We therefore assume that miRNAs may be key regulators in the crosstalk between the Sclerotinia resistance and the flowering time cascades. In frame of a PhD thesis following activities are planned:
 

  • Characterization of the three activation-tagged Arabidopsis mutants and functional analysis of targeted/activated genes

 

  • Identification of key miRNAs, target genes and miRNA-target-interactions involving the crosstalk between the Sclerotinia resistance and the bolting/flowering signal cascades

 

  • Possible application of the results for the oilseed rape resistance breeding