ETHYLENE RESPONSE FACTOR (ERF) genes modulate plant root exudate composition and the attraction of plant parasitic nematodes

Plant root exudates are compositionally diverse, plastic and adaptive. Ethylene signalling influences the attraction of plant parasitic nematodes (PPNs), presumably through the modulation of root exudate composition. Understanding this pathway could lead to new sources of crop parasite resistance. Here we have used Virus-Induced Gene Silencing (VIGS) to knockdown the expression of two ETHYLENE RESPONSE FACTOR ( ERF ) genes, ERF-E2 and ERF-E3 in tomato. Root exudates are significantly more attractive to the PPNs Meloidogyne incognita , and Globodera pallida following knockdown of ERF-E2 , which has no impact on the attraction of Meloidogyne javanica . Knockdown of ERF-E3 has no impact on the attraction of Meloidogyne or Globodera spp. GC-MS analysis revealed substantial changes in root exudate composition relative to controls. However, these changes do not alter the attraction of rhizosphere microbes Bacillus subtilis or Agrobacterium tumefaciens . This study further supports the potential of engineering plant root exudate for parasite control, through the modulation of plant genes.