The heterologous expression of a <i>Glycine max</i> homolog of NONEXPRESSOR OF PR1 (NPR1) and α-hydroxynitrile glucosidase suppresses parasitism by the root pathogen <i>Meloidogyne incognita</i> in <i>Gossypium hirsutum</i>

Experiments in <i>Glycine max</i> (soybean) identified the expression of the salicylic acid signaling and defense gene NONEXPRESSOR OF PR1 (NPR1) in root cells (i.e., syncytium) parasitized by the plant parasitic nematode <i>Heterodera glycines</i> undergoing the process of resistance. Gm-NPR1-2 overexpression in <i>G. max</i> effectively suppresses parasitism by <i>H. glycines</i>. The heterologous expression of Gm-NPR1-2 in <i>Gossypium hirsutum</i> impairs the ability of the parasitic nematode <i>Meloidogyne incognita</i> to form root galls, egg sacs, eggs and second-stage juvenile (J2) nematodes. In related experiments, a <i>G. max</i> β-glycosidase (Gm-βg-4) related to <i>Lotus japonicus</i> secreted defense gene α-hydroxynitrile glucosidase LjBGD7 suppresses <i>M. incognita</i> parasitism. The results identify a cumulative negative effect that the transgenes have on <i>M. incognita</i> parasitism and demonstrate that the <i>G. max</i>–<i>H. glycines</i> pathosystem is a useful tool to identify defense genes that function in other agriculturally relevant plant species to plant parasitic nematodes with different strategies of parasitism.