title: Characterization of a Pipecolic Acid Biosynthesis Pathway Required for Systemic Acquired Resistance.
abstract: Systemic acquired resistance (SAR) is an immune response induced in the distal parts of plants following defense activation in local tissue. Pipecolic acid (Pip) accumulation orchestrates SAR and local resistance responses. Here, we report the identification and characterization of SAR-DEFICIENT4 (SARD4), which encodes a critical enzyme for Pip biosynthesis in Arabidopsis thaliana Loss of function of SARD4 leads to reduced Pip levels and accumulation of a Pip precursor, Δ1-piperideine-2-carboxylic acid (P2C). In Escherichia coli, expression of the aminotransferase ALD1 leads to production of P2C and addition of SARD4 results in Pip production, suggesting that a Pip biosynthesis pathway can be reconstituted in bacteria by coexpression of ALD1 and SARD4. In vitro experiments showed that ALD1 can use l-lysine as a substrate to produce P2C and P2C is converted to Pip by SARD4. Analysis of sard4 mutant plants showed that SARD4 is required for SAR as well as enhanced pathogen resistance conditioned by overexpression of the SAR regulator FLAVIN-DEPENDENT MONOOXYGENASE1. Compared with the wild type, pathogen-induced Pip accumulation is only modestly reduced in the local tissue of sard4 mutant plants, but it is below detection in distal leaves, suggesting that Pip is synthesized in systemic tissue by SARD4-mediated reduction of P2C and biosynthesis of Pip in systemic tissue contributes to SAR establishment.
authors.affiliation: Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4, Canada.
authors.forename: Pingtao
authors.identifier: 0000-0002-3535-6053
authors.initials: P
authors.lastname: Ding
authors.affiliation: Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37073 Goettingen, Germany.
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Rekhter
authors.affiliation: Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4, Canada.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37073 Goettingen, Germany.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Feussner
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver BC V6T 1Z4, Canada.
authors.forename: Lucas
authors.initials: L
authors.lastname: Busta
authors.affiliation: Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37073 Goettingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Haroth
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4, Canada.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4, Canada.|Department of Chemistry, University of British Columbia, Vancouver BC V6T 1Z4, Canada.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Jetter
authors.affiliation: Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37073 Goettingen, Germany ifeussn@gwdg.de yuelin.zhang@ubc.ca.|Department of Plant Biochemistry, Georg-August-University, Goettingen Center for Molecular Biosciences, D-37073 Goettingen, Germany.
authors.forename: Ivo
authors.identifier: 0000-0002-9888-7003
authors.initials: I
authors.lastname: Feussner
authors.affiliation: Department of Botany, University of British Columbia, Vancouver BC V6T 1Z4, Canada ifeussn@gwdg.de yuelin.zhang@ubc.ca.
authors.forename: Yuelin
authors.identifier: 0000-0002-3480-5478
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D010875:Pipecolic Acids / Q000378:metabolism*; D000637:Transaminases / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010875:Pipecolic Acids; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); C487185:AGD2-LIKE DEFENSE RESPONSE PROTEIN1, Arabidopsis; D000637:Transaminases