Reproduction

Pollination

  • Pollination
    • self vs non-self recognition
      • Self incompatibility ensures cross-fertilization
      • S locus encodes components of recognition
        • SRK a kinase expressed in stigma PM
          • Found in papillae cells, interacts with SCR
        • SCR expressed in pollen
          • Peptide secreted by microspore and tapetal cells
          • Issues of sporophyte or gametophyte origin
      • Self rejection pathway
        • Pollen complex with SRK endocytosed and degraded
        • Same papilla can detect self simultaneously with cross
    • pollen tube elongation
      • Tip growth
        • Ca++ gradient
        • Actin necessary
      • Water relations
        • Water uptake from surrounding tract
    • egg cell signals