An NDR1/HIN1-like gene identified in Fraxinus excelsior L. may trigger defence mechanisms in response to virus infection

The defence-associated NDR1/HIN1-like (NHL) gene plays an important role in triggering plant defences in response to biotic stresses. The NHL gene is involved in gene-for-gene-mediated resistance mechanisms in response to attack by bacterial, fungal, and viral pathogens. Our study investigated the variation in 72 virus defence gene candidates annotated in the F. excelsior genome. Among all single nucleotide polymorphisms (SNPs) and indels detected in these candidates, one polymorphic site in the NDR1/HIN1-like protein-encoding gene was able to distinguish between common ash samples with different infection and symptomatic statuses. The SNP was a nonsynonymous substitution that would result in an amino acid change. The variation detected here may have an impact on pattern recognition and therefore affect the immune response, indicating tolerance/susceptibility to viruses of common ash. The identified marker may help in successfully identifying individuals with a low level of susceptibility to viral diseases.