title: Gametophytic self-incompatibility inhibits pollen tube growth using different mechanisms.
abstract: Self-incompatibility (SI) is one of the most important mechanisms used by plants to prevent self-pollination and consequently inbreeding. It is genetically controlled by the S-locus, which allows the recognition and rejection of 'self' (S-phenotypically identical) pollen. Gametophytically controlled SI (GSI) is the most widespread SI system. To date, only two forms have been elucidated in detail at the molecular level, revealing two different stigmatic S-genes. Here we summarize the evidence for the use of two different mechanisms to inhibit incompatible pollen tube growth. Because the limited data suggest the independent evolution of these two GSI systems, it would be interesting to explore other GSI systems to determine the extent of the mechanistic diversity.
authors.affiliation: School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, UK B15 2TT. v.e.franklin-tong@bham.ac.uk
authors.forename: Noni V E
authors.initials: NV
authors.lastname: Franklin-Tong
authors.forename: F Chris H
authors.initials: FC
authors.lastname: Franklin
mesh_terms: D003433:Crosses, Genetic; D005298:Fertility / Q000235:genetics / Q000502:physiology; D035264:Flowers / Q000235:genetics / Q000254:growth & development*; D008024:Ligands; D063245:Plant Development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000235:genetics; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
chemical_list: D008024:Ligands; C099641:PRS3S protein, Papaver rhoeas; D010940:Plant Proteins; D012260:Ribonucleases; C022542:ribonuclease S