title: Arabidopsis thaliana GLUTATHIONE-S-TRANSFERASE THETA 2 interacts with RSI1/FLD to activate systemic acquired resistance.
abstract: A partly infected plant develops systemic acquired resistance (SAR) and shows heightened resistance during subsequent infections. The infected parts generate certain mobile signals that travel to the distal tissues and help to activate SAR. SAR is associated with epigenetic modifications of several defence-related genes. However, the mechanisms by which mobile signals contribute to epigenetic changes are little known. Previously, we have shown that the Arabidopsis REDUCED SYSTEMIC IMMUNITY 1 (RSI1, alias FLOWERING LOCUS D; FLD), which codes for a putative histone demethylase, is required for the activation of SAR. Here, we report the identification of GLUTATHIONE-S-TRANSFERASE THETA 2 (GSTT2) as an interacting factor of FLD. GSTT2 expression increases in pathogen-inoculated as well as pathogen-free distal tissues. The loss-of-function mutant of GSTT2 is compromised for SAR, but activates normal local resistance. Complementation lines of GSTT2 support its role in SAR activation. The distal tissues of gstt2 mutant plants accumulate significantly less salicylic acid (SA) and express a reduced level of the SA biosynthetic gene PAL1. In agreement with the established histone modification activity of FLD, gstt2 mutant plants accumulate an enhanced level of methylated and acetylated histones in the promoters of WRKY6 and WRKY29 genes. Together, these results demonstrate that GSTT2 is an interactor of FLD, which is required for SAR and SAR-associated epigenetic modifications.
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
authors.forename: Zeeshan Zahoor
authors.initials: ZZ
authors.lastname: Banday
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
authors.forename: Ashis Kumar
authors.initials: AK
authors.lastname: Nandi
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate / Q000235:genetics / Q000502:physiology; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins; D005982:Glutathione Transferase; C479923:flowering locus D protein, Arabidopsis; D006655:Histone Deacetylases
keywords: epigenetic modifications; flowering locus D; glutathione-S-transferase; phenylalanine ammonia lyase 1; reduced systemic immunity 1; salicylic acid; systemic acquired resistance