Parasitism of on Different Nematodes and Its Endophytism Promoting Plant Growth and Resistance against Root-Knot Nematodes.

The endoparasitic fungus is an important biocontrol agent of cyst nematodes in nature. To determine the potential parasitism of the fungus on a non-natural host, the pinewood nematode () living in pine trees and the endophytic ability of the fungus on plants, in this paper, we first constructed and utilized a green fluorescent protein (GFP)-tagged HR02 transformant to observe the fungal infection process on . and its colonization on roots. Then, we compared the fungal parasitism on three species of nematodes with different lifestyles, and we found that the fungal parasitism is correlated with nematode species and stages. The parasitic effect of on adults of is similar to that on second-stage juveniles (J2) of the root-knot nematode after 24 h of inoculation, although the virulence of the fungus to second-stage juveniles of is stronger than that to those of and . Moreover, the endophytism of was confirmed. By applying an appropriate concentration of conidial suspension (5 × 10 spores/mL) in rhizosphere soil, it was found that the endophytic fungus can promote growth and reproduction, as well as improve host resistance against Our results provide a deeper understanding of the fungus as a promising biocontrol agent against plant-parasitic nematodes.