Fruit Development

  • Fruit development
    • Patterning
      • Carpel development requires AG and SEP genes (MADS box TFs)
      • Genes only in flowering plants, common to all
      • Dry fruits need to have a means of opening, which is
        regulated
    • Carbohydrate import, storage as starch
    • Polyphenolic synthesis
      • Associated with pigment
      • Also associated with lignification of dry fruit carpel wall
  • Fruit ripening
    • Starch conversion to simple sugars
    • Wall breakdown
      • Galactosidases, glucosidases
    • Ethylene signaling
      • Receptor family has five members of two types
        • ETR1 and ERS1 form one type
          • Ethylene binding and dimerization at N terminal
          • His kinase domain at C terminal
            • Like in bacterial two component signaling systems
        • ETR2, ERS2, and EIN4 lack His kinase domain, have
          different kinase domain
      • Signaling pathway
        • CTR1 is a negative regulator
          • Mutant shows constitutive triple response
            Radial swelling, hypocotyl inhibition, hook
            opening
          • Encodes product homologous to MAPKKK proteins