Self-incompatibility triggers irreversible oxidative modification of proteins in incompatible pollen
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ABSTRACT: Self-incompatibility (SI) is used by many angiosperms to prevent self-fertilization and inbreeding. In Papaver rhoeas interaction of cognate pollen and pistil S-determinants triggers programmed cell death (PCD) of incompatible pollen. We previously identified that reactive oxygen species (ROS) signals to SI-PCD. ROS induced oxidative post-translational modifications (oxPTMs) can regulate protein structure and function. Here we have identified and mapped oxPTMs triggered by SI in incompatible pollen. Notably, SI-induced pollen had numerous irreversible oxidative modifications; untreated pollen had virtually none. Our data provide the first analysis of the protein targets of ROS in the context of SI-induction and represent a milestone because currently there are few reports of irreversible oxPTMs in plants. Strikingly, cytoskeletal proteins and enzymes involved in energy metabolism are a prominent target. Oxidative modifications to a phosphomimic form of a pyrophosphatase result in a reduction of its activity. Therefore, our results demonstrate irreversible oxidation of pollen proteins during SI and show that this can affect protein function. We suggest that this reduction in cellular activity could lead to PCD.
INSTRUMENT(S): LTQ Orbitrap Velos
ORGANISM(S): Papaver Rhoeas (ncbitaxon:33128)
SUBMITTER: Vernonica Franklin-Tong
PROVIDER: MSV000085216 | MassIVE | Thu Apr 02 03:10:00 BST 2020
REPOSITORIES: MassIVE
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