title: Global Regulation of Plant Immunity by Histone Lysine Methyl Transferases.
abstract: Posttranslational modification of histones modulates gene expression affecting diverse biological functions. We showed that the Arabidopsis thaliana histone methyl transferases SET DOMAIN GROUP8 (SDG8) and SDG25 regulate pep1-, flg22-, and effector-triggered immunity as well as systemic acquired resistance. Genome-wide basal and induced transcriptome changes regulated by SDG8 and/or SDG25 showed that two genes of the SDG-dependent transcriptome, CAROTENOID ISOMERASE2 (CCR2) and ECERIFERUM3 (CER3), were also required for plant immunity, establishing mechanisms in defense functions for SDG8 and SDG25. CCR2 catalyzes the biosynthesis of carotenoids, whereas CER3 is involved in the biosynthesis of cuticular wax. SDG8 and SDG25 affected distinct and overlapping global and locus-specific histone H3 lysine 4 (H3K4) and histone H3 lysine 36 (H3K36) methylations. Loss of immunity in sdg mutants was attributed to altered global and CCR2- and CER3-specific histone lysine methylation (HLM). Loss of immunity in sdg, ccr2, and cer3 mutants was also associated with diminished accumulation of lipids and loss of cuticle integrity. In addition, sdg8 and sdg25 mutants were impaired in H2B ubiquitination (H2Bubn) at CCR2, CER3, and H2Bubn regulated R gene, SNC1, revealing crosstalk between the two types of histone modifications. In summary, SDG8 and SDG25 contribute to plant immunity directly through HLM or indirectly through H2Bubn and by regulating expression of plant immunity genes, accumulation of lipids, biosynthesis of carotenoids, and maintenance of cuticle integrity.
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Sanghun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Fuyou
authors.identifier: 0000-0002-5020-4496
authors.initials: F
authors.lastname: Fu
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Siming
authors.initials: S
authors.lastname: Xu
authors.affiliation: Division of Applied Life Sciences (BK 21 Program), Gyeongsang National University, Jinju City 660-701, Korea.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Applied Life Sciences (BK 21 Program), Gyeongsang National University, Jinju City 660-701, Korea.
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907 mengiste@purdue.edu.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Mengiste
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D019755:Carbon-Carbon Lyases; D018506:Gene Expression Regulation, Plant; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D057865:Plant Immunity / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D019755:Carbon-Carbon Lyases; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones; D009687:Nuclear Proteins; C556085:LAZ2 protein, Arabidopsis; C103487:At5g57800 protein, Arabidopsis