N -hydroxy-pipecolic acid is a mobile metabolite that induces systemic disease resistance in Arabidopsis

Abstract

Systemic acquired resistance (SAR) is a global response in plants induced at the site of infection that leads to long-lasting and broad-spectrum disease resistance at distal, uninfected tissues. Despite the importance of this priming mechanism, the identity and complexity of defense signals that are required to initiate SAR signaling is not well understood. In this paper, we describe a metabolite, -hydroxy-pipecolic acid (-OH-Pip) and provide evidence that this mobile molecule plays a role in initiating SAR signal transduction in We demonstrate that FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1), a key regulator of SAR-associated defense priming, can synthesize-OH-Pip from pipecolic acid , and exogenously applied-OH-Pip moves systemically in and can rescue the SAR-deficiency of mutants. We also demonstrate that -OH-Pip treatment causes systemic changes in the expression of pathogenesis-related genes and metabolic pathways throughout the plant and enhances resistance to a bacterial pathogen. This work provides insight into the chemical nature of a signal for SAR and also suggests that the-OH-Pip pathway is a promising target for metabolic engineering to enhance disease resistance.

An iron (II) dependent oxygenase performs the last missing step of plant lysine catabolism

“…Recent studies show that the lysine-derived intermediates pipecolate and N-hydroxypipecolate can initiate systemic acquired resistance (SAR) in plants. 25,26 SAR, a global response, grants lasting broad-spectrum disease protection in uninfected tissue. 27 In bacteria pipecolate is often catabolized to 2OA, suggesting that HglS homologs should receive future attention when studying pipecolate metabolism in plants.…”

JMJ14 encoded H3K4 demethylase modulates immune responses by regulating defence gene expression and pipecolic acid levels

“…Unlike jmj14 , exogenous Pip was able to fully restore SAR in ald1 plants (Navarova et al , ; C. Wang et al , ), which suggests that Pip deficiency alone might not account for SAR defect in jmj14 plants. Considering JMJ14 also regulated FMO1 expression, which acts downstream of Pip (Chen et al , ; Hartmann et al , ), lends to the possibility that a SAR defect in jmj14 may be associated with both Pip and its downstream signal NHP. However, considering jmj14 only shows attenuated expression of FMO1 , exogenous Pip should have compensated for any reduction in NHP levels and restored SAR in jmj14 plants.…”

“…Wang et al, 2018), which suggests that Pip deficiency alone might not account for SAR defect in jmj14 plants. Considering JMJ14 also regulated FMO1 expression, which acts downstream of Pip (Chen et al, 2018;, lends to the possibility that a SAR defect in jmj14 may be associated with both Pip and its downstream signal NHP. However,…”

“…The sard4 plants has been reported to show normal (Hartmann et al , ) or compromised SAR (Ding et al , ) and the reason for this variable SAR phenotype is not clear. Pip is hydroxylated to N‐hydroxy‐pipecolic acid (NHP) by FLAVIN‐DEPENDENT MONOOXYGENASE 1 (FMO1) and FMO1 is essential for biologically induced SAR (Mishina & Zeier, ; Chen et al , ; Hartmann et al , ). NHP confers SAR on both ald1 and fmo1 plants (Chen et al , ; Hartmann et al , ), suggesting that NHP acts downstream of Pip (Hartmann & Zeier, ).…”

“…Pip is hydroxylated to N‐hydroxy‐pipecolic acid (NHP) by FLAVIN‐DEPENDENT MONOOXYGENASE 1 (FMO1) and FMO1 is essential for biologically induced SAR (Mishina & Zeier, ; Chen et al , ; Hartmann et al , ). NHP confers SAR on both ald1 and fmo1 plants (Chen et al , ; Hartmann et al , ), suggesting that NHP acts downstream of Pip (Hartmann & Zeier, ). Relationship between NHP and other SAR inducers remains unknown at present.…”