From nutrition to protection: the role of arbuscular mycorrhizal fungi in the interactions of plants with endoparasitic nematodes – A meta-analysis

Abstract

Aims We conducted an updated meta-analysis on how arbuscular mycorrhizal fungi (AMF) improve the growth and phosphorus (P) and nitrogen (N) nutrition of plants infected by plant parasitic nematodes (PPN), and the effect of PPN on AMF root colonization, depending on AMF orders and PPN life habits. Methods We considered data from greenhouse experiments with AMF and PPN inoculation to perform a meta-analysis. We also correlated the effect of AMF on PPN performance and plant nutrition with plant biomass. Furthermore, we correlated AMF root colonization level on PPN effect with plant biomass and on AMF effect with PPN performance. Results With sedentary PPN, our results suggest that AMF increased plant biomass and nutrients. In plants infected with migratory PPN, N increased with all AMFs, but biomass increased only with Glomerales. While Glomerales and Gigasporales reduced the populations of sedentary PPN, mixed inoculum and Diversisporales had no effect. Conversely, mixed inoculum reduced migratory PPN while Glomerales was not effective. PPN infection did not affect AMF colonization. We found a positive correlation between the effect of AMF inoculation on P nutrition and on plant biomass, and also between AMF colonization level and the effect of PPN on plant biomass, while root colonization level was not correlated with the effect of AMF on PPN. Conclusions AMF may confer increased pest tolerance and/or resistance mechanisms to PPN-infected plants, with varying outcomes depending on the AMF phylogenetic orders and PPN life habits, suggesting unexplored mechanisms of biocontrol that could contribute to sustainable crop protection strategies.