Self-incompatibility triggers irreversible oxidative modification of proteins in incompatible pollen

Authors Organisations
  • Tamanna Haque(Author)
    University of Birmingham
  • Deborah Eaves(Author)
    University of Birmingham
  • Zongcheng Lin(Author)
    Ghent University
  • Gleidiane Zampronio(Author)
    University of Warwick
  • Helen Cooper(Author)
    University of Birmingham
  • Maurice Bosch(Author)
  • Nicholas Smirnoff(Author)
    University of Exeter
  • Vernonica E. Franklin-Tong(Author)
    University of Birmingham
Type Article
Original languageEnglish
Pages (from-to)1391-1404
Number of pages14
JournalPlant Physiology
Issue number3
Early online date22 Apr 2020
Publication statusPublished - 01 Jul 2020
View graph of relations
Citation formats


Self-incompatibility (SI) is used by many angiosperms to prevent self-fertilization and inbreeding. In common poppy (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) signal 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 while untreated pollen had virtually none. Our data provide a valuable analysis of the protein targets of ROS in the context of SI-induction and comprise a benchmark because currently there are few reports of irreversible oxPTMs in plants. Strikingly, cytoskeletal proteins and enzymes involved in energy metabolism are a prominent target of ROS. 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 provide evidence that this modification can affect protein function. We suggest that this reduction in cellular activity could lead to PCD.