Verticillium dahliae is a soil-borne fungal pathogen with a broad host range. Comparative genomics and phylogenetic analyses identified the virulence gene Ave1, which has many homologs in plants, several other fungi and the bacterial pathogen Xanthomonas axonopodis pv. citri (Xac). The homology is determined by the presence of a highly conserved sequence coding for a so-called plant natriuretic peptide (PNP). PNPs constitute a class of systemically mobile molecules that function in plant homeostasis and growth. The microbial homolog characterized to date is XacPNP. Similar to Arabidopsis PNP-A, XacPNP alters physiological responses such as stomatal opening in plants. During infection, XacPNP is required for the suppression of host cell death to establish favourable conditions for the survival of the bacterial biotroph. In vitro stomatal aperture assays in Arabidopsis epidermis tissue demonstrated that also Ave1 from V. dahliae retains an active PNP site. Interestingly, however, complementation of ΔAve1 in V. dahliae with homologous sequences from tomato or Xac did not result in the recovery of V. dahliae virulence. In addition, structural modelling suggests that, compared to its homologs, V. dahliae Ave1 has a highly variable surface opposite the conserved PNP site. These findings indicate that Ave1 may have functionally diverged from its microbial and plant homologs and obtained an additional function that contributes to V. dahliae virulence.
|Publication status||Published - 2016|
|Event||XVII International Congress on Molecular Plant-Microbe Interactions - Portland, Oregon, United States|
Duration: 17 Jul 2016 → 21 Jul 2016
|Conference||XVII International Congress on Molecular Plant-Microbe Interactions|
|Period||17/07/16 → 21/07/16|