title: Pathogen Infection and MORC Proteins Affect Chromatin Accessibility of Transposable Elements and Expression of Their Proximal Genes in Arabidopsis.
abstract: To assess the role of MORC1 in epigenetics in relation to plant immunity, genome-wide chromatin accessibility was compared between mock- or Pseudomonas syringae pv. tomato-inoculated wild type (WT) Arabidopsis, the morc1/2 double mutant, or both. Most changes in chromatin accessibility, scored by DNase I hypersensitive sites (DHSs), were located in the promoters of genes and transposable elements (TEs). Comparisons between morc1/2 and WT receiving the same treatment revealed differential DHSs (dDHSs) predominantly associated with heterochromatic TEs. By contrast, comparisons between mock- and P. syringae pv. tomato-inoculated plants from the same genotype showed dDHSs associated with biotic and abiotic stress-related genes; a smaller but significant population was in TEs. Moreover, many defense genes, including PR-1, PR-2, and PR-5, were proximal to P. syringae pv. tomato-induced, TE-associated dDHSs. A random subset of these defense genes showed moderately delayed or reduced expression or both in P. syringae pv. tomato-infected morc1/2 as compared with WT. MORC1 was physically bound to chromatin in a P. syringae pv. tomato infection-responsive manner at sites dispersed throughout the genome. Notably, silencing of TE-associated dDHSs proximal to these infection-induced, MORC1-interacting sites led to significant suppression of P. syringae pv. tomato-induced transcription of adjacent defense genes, including PR-1. These results provide evidence that MORC1 is associated with TEs and suggest that a subset of these TEs may help regulate their proximal defense genes.
authors.affiliation: 1 Department of Biology, Texas State University, San Marcos, TX, U.S.A.
authors.forename: Yogendra
authors.initials: Y
authors.lastname: Bordiya
authors.affiliation: 2 Boyce Thompson Institute for Plant Research, Ithaca, NY, U.S.A.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: 1 Department of Biology, Texas State University, San Marcos, TX, U.S.A.
authors.forename: Ji-Chul
authors.initials: JC
authors.lastname: Nam
authors.affiliation: 1 Department of Biology, Texas State University, San Marcos, TX, U.S.A.
authors.forename: April C
authors.initials: AC
authors.lastname: Bonnard
authors.affiliation: 2 Boyce Thompson Institute for Plant Research, Ithaca, NY, U.S.A.
authors.forename: Hyong Woo
authors.initials: HW
authors.lastname: Choi
authors.affiliation: 3 Department of Molecular Biosciences, The University of Texas at Austin, U.S.A.; and.
authors.forename: Bum-Kyu
authors.initials: BK
authors.lastname: Lee
authors.affiliation: 3 Department of Molecular Biosciences, The University of Texas at Austin, U.S.A.; and.
authors.forename: Jonghwan
authors.initials: J
authors.lastname: Kim
authors.affiliation: 2 Boyce Thompson Institute for Plant Research, Ithaca, NY, U.S.A.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Klessig
authors.affiliation: 2 Boyce Thompson Institute for Plant Research, Ithaca, NY, U.S.A.|4 USDA Robert W. Holley Center for Agriculture and Health, Tower Road, Ithaca, NY, U.S.A.
authors.forename: Zhangjun
authors.initials: Z
authors.lastname: Fei
authors.affiliation: 1 Department of Biology, Texas State University, San Marcos, TX, U.S.A.
authors.forename: Hong-Gu
authors.initials: HG
authors.lastname: Kang
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D044224:Pseudomonas syringae / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D004251:DNA Transposable Elements; D000251:Adenosine Triphosphatases; C573242:MORC1 protein, Arabidopsis