Benoit Laurent, Magalie Moinard, C. Spataro, Sylvain Chéreau, Enric Zehraoui, Richard Blanc, Pauline Lasserre, Nadia Ponts, Marie Foulongne-Oriol (2021)
QTL mapping in Fusarium graminearum identified an allele of FgVe1 involved in reduced aggressiveness.

Fungal Genetics and Biology - Pre proof - https://doi.org/10.1016/j.fgb.2021.103566

Highlights 

Using two Fusarium graminearum strains with contrasting levels of aggressiveness towards wheat, QTL mapping, genome mining, and functional genetics, a rare mutation in FgVe1 was identified at a QTL location on chromosome 1 .This mutation is involved in the reduction of aggressiveness.

Abstract:

Fusarium graminearum is one of the most frequent causal agents of the Fusarium Head Blight, a cereal disease spread throughout the world, reducing grain production and quality. F. graminearum isolates are genetically and phenotypically highly diverse. Notably, remarkable variations of aggressiveness between isolates have been observed, which could reflect an adaptive potential of this pathogen. In this study, we aimed to characterize the genetic basis of aggressiveness variation observed in an F1 population (n=94), for which genome sequences of both parental strains are available. Aggressiveness was assessed by a panel of in planta and in vitro proxies during two phenotyping trials including, among others, disease severity and mycotoxin accumulation in wheat spike. One major and single QTL was mapped for all the traits measured, on chromosome I, that explained up to 90% of the variance for disease severity. The confidence interval at the QTL spanned 1.2 Mb and contained 428 genes on the reference genome. Of these, four candidates were selected based on the postulate that a non-synonymous mutation affecting protein function may be responsible for phenotypic differences. Finally, a new mutation was identified and functionally validated in the gene FgVe1, coding for a velvet protein known to be involved in pathogenicity and secondary metabolism production in several fungi.