Description:
<jats:title>Summary</jats:title>
<jats:p>Cyst nematodes are plant parasites that cause significant crop loss in wheat and other crops. Infective juveniles invade roots and induce syncytial feeding structures as the only source of nutrients throughout their life. A previous genome-wide association study in wheat identified amino acid permease 6 (<jats:italic>TaAAP6</jats:italic>) to be linked to susceptibility to the cereal cyst nematode <jats:italic>Heterodera filipjevi</jats:italic>. To characterise the role of <jats:italic>AAP6</jats:italic> during nematode parasitism, we analysed the expression of <jats:italic>TaAAP6</jats:italic> and the Arabidopsis orthologue <jats:italic>AtAAP6. TaAAP6</jats:italic> was found to be highly expressed in nematode-infected roots of susceptible wheat, whereas it was not upregulated in nematode-infected roots of resistant accessions. <jats:italic>AtAAP6</jats:italic> was also found to be highly upregulated in nematode-induced syncytia compared with non-infected roots. Infection assays with an <jats:italic>AtAAP6</jats:italic> knock-out mutant revealed reduction in developing females, female size, and size of female-associated syncytia, thus indicating the importance of AAP6 in cyst nematode parasitism.</jats:p>