Effect of Pythium arrhenomanes elicitor NLP on the interaction with Meloidogyne graminicola in rice
R. VERBEEK (1), E. Rom Mas (2), M. Sikder (2), M. Höfte (2) (1) Ghent University, Belgium; (2) Ghent University, Belgium

Traditional rice cultivation is more and more being replaced by an aerobic cultivation system due to fresh water scarcity. This shift however, introduced a new array of pathogens to affect rice cultivation. Oomycetes (Pythium spp.) and root-knot nematode Meloidogyne graminicola are the two predominant root pathogens in aerobic rice. We showed that P. arrhenomanes and M. graminicola interact antagonistically in the rice roots, resulting in higher filled grain weight when they co-occur in the rice roots compared to single infections. The presence of P. arrhenomanes was shown to lower penetration, slower development and decreased reproduction of M. graminicola. However, the mechanisms of this antagonism remain elusive. Recently, we found that application of P. arrhenomanes secretions on rice roots caused root necrosis and this was correlated with reduced M. graminicola penetration. In a search for possible effectors/elicitors in the secretome of P. arrhenomanes, we found that at least two NLPs (Nep1 (Necrosis and Ethylene inducing protein)-like proteins) are expressed by P. arrhenomanes after infection on rice roots. Currently, we are using CRISPR/Cas9 to create a knock-out in the conserved region of these NLP-genes, to knock-out both NLPs and to study the effect on P. arrhenomanes virulence and to study the effects of NLPs on the antagonism between P. arrhenomanes and M. graminicola in rice roots.

Abstract Number: P12-403
Session Type: Poster