Global genome-wide DNA methylation patterns induced by the beet cyst nematode Heterodera schachtii in Arabidopsis roots
T. HEWEZI (1), T. Lane (1), S. Piya (1), A. Rambani (1), J. Rice (1) (1) University of Tennessee, U.S.A.

The hallmark characteristic of the compatible interactions between plant-parasitic cyst nematodes and host plants is the formation of functional multinucleated feeding sites or syncytia in the roots of host plants. To analyze methylome changes associated with the compatible interaction between the beet cyst nematode Heterodera schachtii and Arabidopsis, we used MethylC-Seq method to generate genome-wide, single-base resolution DNA methylomes of Arabidopsis roots during the two distinct stages of syncytium formation and maintenance. Arabidopsis plants were inoculated with H. schachtii and root tissues were collected at 5 and 10 day post inoculation from both infected and non-infected roots from three biological samples. Thousands of differentially methylated regions (DMRs) were identified at both time points, indicating that the methylome of Arabidopsis roots is significantly altered during syncytium formation and maintenance stages. However, 10% of the DMRs overlapped between the 5- and 10- day time points, suggesting that each stage is associated with distinct patterns of DNA methylation. Our analysis also revealed that H. schachtii induces hypomethylation to much higher degree than hypermethylation. In addition, we found that CpG methylation was mainly associated with protein-coding genes, whereas methylation in CHG and CHH contexts was predominantly associated with transposable elements. Interestingly, about 25% of the differentially methylated genes in the promoter region were previously identified as syncytium differentially expressed genes, suggesting a role of DNA methylation in regulating gene expression changes in the syncytium. Gene ontology classification of these genes provided unprecedented insights into the biological process that are under methylation control in the nematode-induced syncytium.

Abstract Number: P11-363
Session Type: Poster