Background:Plant-parasitic nematodes and herbivorous insects have a significant negative impact on global cropproduction. A successful approach to protect crops from these pests is thein plantaexpression of nematotoxic orentomotoxic proteins such as crystal proteins fromBacillus thuringiensis(Bt) or plant lectins. However, the efficacy ofthis approach is threatened by emergence of resistance in nematode and insect populations to these proteins. Tosolve this problem, novel nematotoxic and entomotoxic proteins are needed. During the last two decades, severalcytoplasmic lectins from mushrooms with nematicidal and insecticidal activity have been characterized. In thisstudy, we tested the potential ofMarasmius oreadesagglutinin (MOA) to furnish Arabidopsis plants with resistancetowards three economically important crop pests: the two plant-parasitic nematodesHeterodera schachtiiandMeloidogyne incognitaand the herbivorous diamondback mothPlutella xylostella. Results:The expression of MOA does not affect plant growth under axenic conditions which is an essentialparameter in the engineering of genetically modified crops. The transgenic Arabidopsis lines showed nearlycomplete resistance toH. schachtii, in that the number of female and male nematodes per cm root was reduced by86–91 % and 43–93 % compared to WT, respectively.M. incognitaproved to be less susceptible to the MOA proteinin that 18–25 % and 26–35 % less galls and nematode egg masses, respectively, were observed in the transgeniclines. Larvae of the herbivorousP. xylostellaforaging on MOA-expression lines showed a lower relative mass gain(22–38 %) and survival rate (15–24 %) than those feeding on WT plants. Conclusions:The results of ourin plantaexperiments reveal a robust nematicidal and insecticidal activity of thefungal lectin MOA against important agricultural pests which may be exploited for crop protection.
