Activation of R‐mediated innate immunity and disease susceptibility is affected by mutations in a cytosolic O‐acetylserine (thiol) lyase in Arabidopsis. (5th November 2012)

• Record Type: Journal Article
• Authors: Tahir, Jibran; Watanabe, Mutsumi; Jing, Hai‐Chun; Hunter, Donald A.; Tohge, Takayuki; Nunes‐Nesi, Adriano; Brotman, Yariv; Fernie, Alisdair R.; Hoefgen, Rainer; Dijkwel, Paul P.
• Is Part Of: Plant journal. Volume 73:Number 1(2013:Jan.)
• Page Start: 118
• Page End: 130
• Publication Date: 2012-11-05
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12021
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12021-abs-0001"> <title>Summary</title> <p> <italic>O</italic>‐acetylserine (thiol) lyases (OASTLs) are evolutionarily conserved proteins among many prokaryotes and eukaryotes that perform sulfur acquisition and synthesis of cysteine. A mutation in the cytosolic OASTL‐A1 protein ONSET OF LEAF DEATH3 (OLD3) was previously shown to reduce the OASTL activity of the old3‐1 protein <italic>in vitro</italic> and cause auto‐necrosis in specific Arabidopsis accessions. Here we investigated why a mutation in this protein causes auto‐necrosis in some but not other accessions. The auto‐necrosis was found to depend on <italic>Recognition of Peronospora Parasitica 1</italic> (<italic>RPP1</italic>)‐like disease resistance <italic>R</italic> gene(s) from an evolutionarily divergent <italic>R</italic> gene cluster that is present in L<italic>er</italic>‐0 but not the reference accession Col‐0. <italic>RPP1</italic><italic>‐</italic>like gene(s) show a negative epistatic interaction with the <italic>old3</italic>‐<italic>1</italic> mutation that is not linked to reduced cysteine biosynthesis. Metabolic profiling and transcriptional analysis further indicate that an effector triggered‐like immune response and metabolic disorder are associated with auto‐necrosis in <italic>old3</italic>‐<italic>1</italic> mutants, probably activated by an <italic>RPP1</italic><italic>‐</italic>like gene. However, the old3‐1 protein in itself results in largely neutral changes in primary plant metabolism, stress defence and immune responses. Finally, we showed that lack of a functional OASTL‐A1 results in enhanced disease susceptibility against infection with virulent and non‐virulent <italic>Pseudomonas syringae</italic> pv. <italic>tomato DC3000</italic> strains. These results reveal an interaction between the cytosolic OASTL and components of plant immunity.</p> </abstract>