Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.

Mitochondria are known for their role in ATP production and generation of reactive oxygen species (ROS), but little is known about the mechanism of their early involvement in plant stress signalling. The role of mitochondrial succinate dehydrogenase (SDH) in salicylic acid (SA) signalling was analys...

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Main Authors: Belt, K., Huang, S., Thatcher, L., Casarotto, H., Singh, Karam, Van Aken, O., Millar, A.
Format: Journal Article
Published: American Society of Plant Biologists 2017
Online Access:http://hdl.handle.net/20.500.11937/51680
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author Belt, K.
Huang, S.
Thatcher, L.
Casarotto, H.
Singh, Karam
Van Aken, O.
Millar, A.
author_facet Belt, K.
Huang, S.
Thatcher, L.
Casarotto, H.
Singh, Karam
Van Aken, O.
Millar, A.
author_sort Belt, K.
building Curtin Institutional Repository
collection Online Access
description Mitochondria are known for their role in ATP production and generation of reactive oxygen species (ROS), but little is known about the mechanism of their early involvement in plant stress signalling. The role of mitochondrial succinate dehydrogenase (SDH) in salicylic acid (SA) signalling was analysed using two mutants; disrupted in stress response 1 (dsr1) which is a point mutation in SDH1 identified in a loss of SA signalling screen, and a knockdown mutant (sdhaf2) for SDH assembly factor 2 that is required for FAD insertion into SDH1. Both mutants showed strongly decreased SA-inducible stress promoter responses and low SDH maximum capacity compared to wild type; while dsr1 also showed low succinate affinity, low catalytic efficiency and increased resistance to SDH competitive inhibitors. The SA-induced promoter responses could be partially rescued in sdhaf2, but not in dsr1, by supplementing the plant growth media with succinate. Kinetic characterisation showed that low concentrations of either SA or ubiquinone binding site inhibitors increased SDH activity and induced mitochondrial H2O2 production. Both dsr1 and sdhaf2 showed lower rates of SA-dependent H2O2 production in vitro in line with their low SA-dependent stress signalling responses in vivo. This provides quantitative and kinetic evidence that SA acts at or near the ubiquinone binding site of SDH to stimulate activity and contributes to plant stress signalling by increased rates of mitochondrial H2O2 production, leading to part of the SA-dependent transcriptional response in plant cells.
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institution Curtin University Malaysia
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publishDate 2017
publisher American Society of Plant Biologists
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spelling curtin-20.500.11937-516802023-02-22T06:24:22Z Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase. Belt, K. Huang, S. Thatcher, L. Casarotto, H. Singh, Karam Van Aken, O. Millar, A. Mitochondria are known for their role in ATP production and generation of reactive oxygen species (ROS), but little is known about the mechanism of their early involvement in plant stress signalling. The role of mitochondrial succinate dehydrogenase (SDH) in salicylic acid (SA) signalling was analysed using two mutants; disrupted in stress response 1 (dsr1) which is a point mutation in SDH1 identified in a loss of SA signalling screen, and a knockdown mutant (sdhaf2) for SDH assembly factor 2 that is required for FAD insertion into SDH1. Both mutants showed strongly decreased SA-inducible stress promoter responses and low SDH maximum capacity compared to wild type; while dsr1 also showed low succinate affinity, low catalytic efficiency and increased resistance to SDH competitive inhibitors. The SA-induced promoter responses could be partially rescued in sdhaf2, but not in dsr1, by supplementing the plant growth media with succinate. Kinetic characterisation showed that low concentrations of either SA or ubiquinone binding site inhibitors increased SDH activity and induced mitochondrial H2O2 production. Both dsr1 and sdhaf2 showed lower rates of SA-dependent H2O2 production in vitro in line with their low SA-dependent stress signalling responses in vivo. This provides quantitative and kinetic evidence that SA acts at or near the ubiquinone binding site of SDH to stimulate activity and contributes to plant stress signalling by increased rates of mitochondrial H2O2 production, leading to part of the SA-dependent transcriptional response in plant cells. 2017 Journal Article http://hdl.handle.net/20.500.11937/51680 10.1104/pp.16.00060 American Society of Plant Biologists unknown
spellingShingle Belt, K.
Huang, S.
Thatcher, L.
Casarotto, H.
Singh, Karam
Van Aken, O.
Millar, A.
Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title_full Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title_fullStr Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title_full_unstemmed Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title_short Salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
title_sort salicylic acid-dependent plant stress signalling via mitochondrial succinate dehydrogenase.
url http://hdl.handle.net/20.500.11937/51680