Collaborative Research: Unveiling the molecular mechanism of feeding tube formation by root-knot nematodes: structural and functional insights 

There is an urgent agricultural need for novel approaches to combat the billions of dollars lost annually to the devastating root-knot nematode, an obligate sedentary endoparasite and

global threat to food and fiber crop production. The focus of this project is to resolve the mystery of the root-knot nematode feeding tube, a unique nematode-produced structure that forms within the cytoplasm of plant root cells selectively transformed into giant-cells by the nematode to serve as a nutrient sink leading to successful parasitism. Feeding tubes produced by all species of root-knot nematodes are essential for efficient withdrawal of nutrients from the cytoplasm by the sedentary adult females which require intensive nourishment for several weeks during the production of hundreds of eggs. While the feeding tube has been described at the ultrastructural level, its composition and mechanism of assembly remain an enigma. A combination of immunohistochemistry, structural biology, and protein interaction studies coupled with host-delivered RNA interference is proposed to identify the nematode proteins involved in feeding tube formation and translate this knowledge to develop novel root-knot nematode resistance in crop plants. The composition of feeding tubes and the underlying mechanism of their assembly is currently unknown and presents a truly transformative opportunity for a deeper understanding of root-knot nematode parasitism. The underlying hypothesis is that once adult root-knot nematode females have established giant-cells they secrete one or more proteins through their stylet into these cells that self-assemble into a feeding tube essential for efficient nutrient uptake. A molecular and biochemical understanding of the mechanism of feeding tube formation will enable the development of innovative, broad-spectrum strategies for combating this destructive agricultural pathogen. This project will provide new insights into the molecular basis of feeding tube formation by root-knot nematodes, which in turn will provide critical insight into how these nematodes successfully parasitize a wide range of plant hosts to aid in the design of novel and broad resistance in crop plants. PI Mitchum will partner with the State Botanical Garden of Georgia for field trip adventures and summer camp activities to improve STEM education through hands-on activities that will bring awareness to the hidden enemies lurking below ground that impact our food supply.

Funder: USDA NIFA 

Amount: $800,000 

PI: Melissa Mitchum, College of Agricultural and Environmental Sciences