In a new study, root exudates from mycorrhizal and non-mycorrhizal plants growing at low or high nutrient supply were used in vitro to examine their effects on the growth and fumonisin B1 gene (FUM1) expression of Fusarium proliferatum (Hypocreales: Nectriaceae).
After one day of exposure to root exudates originating from non-mycorrhizal and low nutrient supply treatment, a significant change in the growth of F. proliferatum was measured, which then equalized after 5 days of incubation.
Aside from the fumonisin gene (FUM1) gene, the expression of the mitogen-activated protein kinase gene (HOG1) was also studied using quantitative real-time polymerase chain reaction (qRT-PCR). After 5 days of incubation, mycorrhizal root exudates significantly reduced the expression of the FUM1 gene, irrespective of the extent of the nutrient supplement and colonization level of the target plant.
Similar trends in the expressions of FUM1 and HOG1 genes found in the experiment suggest that arbuscular mycorrhizal fungal colonization did not only affect directly the growth and mycotoxin production of F. proliferatum, but also modulated indirectly a number of other mechanisms. Mycorrhizal inoculation showed potential as a biological control agent in the suppression of fumonisin production by F. proliferatum.