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Alternative oxidase impacts the plant response to biotic stress by influencing the mitochondrial generation of reactive oxygen species
Author(s) -
CVETKOVSKA MARINA,
VANLERBERGHE GREG C.
Publication year - 2013
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12009
Subject(s) - alternative oxidase , respiratory burst , antimycin a , reactive oxygen species , mitochondrion , superoxide , mitochondrial ros , hypersensitive response , nadph oxidase , pseudomonas syringae , chemistry , biology , microbiology and biotechnology , biochemistry , programmed cell death , enzyme , gene , apoptosis
Previously, we showed that inoculation of tobacco with Pseudomonas syringae incompatible pv. maculicola results in a rapid and persistent burst of superoxide (O 2 ‐ ) from mitochondria, no change in amount of mitochondrial alternative oxidase (AOX) and induction of the hypersensitive response (HR). However, inoculation with incompatible pv. phaseolicola resulted in increased AOX, no O 2 ‐ burst and no HR. Here, we show that in transgenic plants unable to induce AOX in response to pv. phaseolicola , there is now a strong mitochondrial O 2 ‐ burst, similar to that normally seen only with pv. maculicola . This interaction did not however result in a HR. This indicates that AOX amount is a key determinant of the mitochondrial O 2 ‐ burst but also that the burst itself is not sufficient to induce the HR. Surprisingly, the O 2 ‐ burst normally seen towards pv. maculicola is delayed in plants lacking AOX. This delay is associated with a delayed HR, suggesting that the burst does promote the HR. A O 2 ‐ burst can also be induced by the complex III inhibitor antimycin A (AA), but is again delayed in plants lacking AOX. The similar mitochondrial response induced by pv. maculicola and AA suggests that electron transport is a target during HR‐inducing biotic interactions.