Abstract：Plant genome DNA methylation plays an important role in regulating gene expression and epigenetic change responded to various stresses. In this study, Maize(Zea mays) of high resistance inbred line R15 and high susceptible inbred line 478 were adopted by inoculating sheath blight pathogen (Rhizoctonia solani Kühn), and pathological changes in maize inbred line R15 were observed by electronic microscope and digital camera technology. The result showed that host was infected by mycelium through the leaf sheath stomata and the change of lesion size revealed the pathogen infection on the host has a certain gradient. The patterns of methylation were analyzed in high resistant inbred line R15 and high susceptible inbred line 478 by methylation-sensitive amplified polymorphism(MSAP), which are all inoculated for 0, 6, 12 and 24 h, respectively and amplified by 24 pairs of selective primers. The results showed hemi-methylation level increased but total methylation level first increased and then decreased in both R15 and 478. However, the level of increase in R15 was higher than that of 478. In conclusion, DNA methylation is closely related with maize resistance to Rhizoctonia solani Kühn and plays an important role in regulating gene expression responded to maize resistance.
