Korean researchers at POSTECH have identified a mechanism by which plants remember pathogen invasion and have a fast and strong disease resistance response, laying the foundation for developing pest-resistant crops. The results of the study were published on 5 May in the journal Genome Biology.

 It is thought that plants use epigenetic* methods to remember previous pathogen attacks. However, the mechanism was not clearly understood.

 *Epigenetics: The study of the regulation of gene expression and the inheritance of altered states of gene expression without changes in DNA sequence. It is mainly known to be regulated by DNA methylation and histone proteins.

 The researchers found that plants with reduced DNA methylation at gene body were more resistant to pathogens. The gene families with altered DNA methylation included genes that respond to stress, and these genes also have distinctive chromatin* characteristics. In addition, genes with decreased DNA methylation at the gene body showed a significant increase in gene expression upon pathogen invasion.

 *Chromatin: Composed of DNA and histone proteins, chromatin is assembled to form chromosomes. 

Professor Hwang explained that the study "revealed that DNA methylation at gene sites, whose function was previously unclear and hypothesised, is associated with the regulation of gene expression." "We will focus on developing eco-friendly, pesticide-free and high-yielding crops by improving disease resistance using epigenetic regulation," he said.

Decreased gene body DNA methylation is associated with hyper activation of defense response gene during pathogen infection

[Reference] Lee S. et al.,(2023) DDM1‑mediated gene body DNA methylation is associated with inducible activation of defense‑related genes in Arabidopsis. Genome biology, DOI:0.1186/s13059-023-02952-7 

[Main Author] Seungchul Lee (POSTECH), Jaemyung Choi (POSTECH), Ildoo Hwang (POSTECH)

 * Contact : Professor Ildoo Hwang ihwang@postech.ac.kr