[Mechanisms of plant disease resistance induced by arbuscular mycorrhizal fungi].

In recent years, the induced disease resistance of plant by Arbuscular Mycorrhizal Fungi (AMF) has become a hot spot in chemo-ecological study and in biocontrol of plant disease. There were many reports indicating that AMF had antagonistic function to soilborne disease pathogen, or could suppress the growth of pathogen, and increase the resistance or tolerance of mycorrhizal plants to soilborne disease. In mycorrhizosphere, there are interactions among microbial community, in which, AMF could suppress the growth of pathogen and promote the growth of beneficial microbe. Thus, AMF may use as biocontrol fungi with other antagonism microbe. There were several hypotheses about the mechanisms of the increased resistance in mycorrhizal plants: (1) improvement of plant nutrient status; (2) competition; (3) changed roots morphology and structure; (4) changed microbial flora in rhizosphere; (5) induced resistance or systematic resistance in plant. After colonized by AMF, phenolic compounds accumulate in plant, and local defense response or systemic defense response occurs. It is necessary to do intensive research on the mechanisms of increased resistance in mycorrhizal plants, because it may help us understand the function of disease resistance of mycorrhiza correctly, and let us use AMF as a new biocontrol method to control soilborne disease in eco-agriculture in the near future.