title: Investigating mechanisms involved in the self-incompatibility response in Papaver rhoeas.
abstract: Sexual reproduction in flowering plants is controlled by recognition mechanisms involving the male gametophyte (the pollen) and the female sporophyte (the pistil). Self-incompatibility (SI) involves the recognition and rejection of self- or incompatible pollen by the pistil. In Papaver rhoeas, SI uses a Ca(2+)-based signalling cascade triggered by the S-protein, which is encoded by the stigmatic component of the S-locus. This results in the rapid inhibition of incompatible pollen tube growth. We have identified several targets of the SI signalling cascade, including protein kinases, the actin cytoskeleton and nuclear DNA. Here, we summarize progress made on currently funded projects in our laboratory investigating some of the components targeted by SI, comprising (i) the characterization of a pollen phosphoprotein (p26) that is rapidly phosphorylated upon an incompatible SI response; (ii) the identification and characterization of a pollen mitogen-activated protein kinase (p56), which exhibits enhanced activation during SI; (iii) characterizing components involved in the reorganization and depolymerization of the actin cytoskeleton during the SI response; and (iv) investigating whether the SI response involves a programmed cell death signalling cascade.
authors.affiliation: School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Thomas
authors.forename: Kim
authors.initials: K
authors.lastname: Osman
authors.forename: Barend H J
authors.initials: BH
authors.lastname: de Graaf
authors.forename: Galina
authors.initials: G
authors.lastname: Shevchenko
authors.forename: Mike
authors.initials: M
authors.lastname: Wheeler
authors.forename: Chris
authors.initials: C
authors.lastname: Franklin
authors.forename: Noni
authors.initials: N
authors.lastname: Franklin-Tong
mesh_terms: D000199:Actins / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D003599:Cytoskeleton / Q000502:physiology; D007178:Inbreeding; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D010207:Papaver / Q000201:enzymology / Q000502:physiology*; D011058:Pollen / Q000502:physiology; D015398:Signal Transduction
chemical_list: D000199:Actins; D020929:Mitogen-Activated Protein Kinase Kinases; D002118:Calcium