Analysis of root-knot nematode early infection events in tomato colonizedby the arbuscular mycorrhizal fungus Glomus mosseae

Abstract: Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts colonizing themajority of vascular plants on earth. The fungi receive photosynthetic carbon from their host,while the plant benefits from improved water and nutrient uptake, resulting in enhanced growthand survival. In addition, AMF have been shown to reduce the occurrence and impact of severalsoil pathogens including plant-parasitic nematodes on a wide range of agricultural crops. A wellestablishedAMF-colonization is a prerequisite for AMF-induced biocontrol against nematodes,both locally and systemically. Apart from these observations however, the defense mechanismsinvolved have rarely been investigated for AMF-nematode interactions. Our experiments indicatethat the presence of the AMF Glomus mosseae reduces root-knot nematode infection, and alreadyinfluences the nematode Meloidogyne incognita in its early stage of plant infection. In order tounderstand the underlying mechanisms of this effect, we are undertaking an in-depth study bymonitoring the AMF-plant-nematode interaction during early root-knot nematode infection.