1 Reproduction and Senescence Katerina Dadakova, Department of Biochemistry Figures adopted from Buchanan et al., Biochemistry & molecular biology of plants Reproduction and Senescence 2 The life cycle of flowering plants Reproduction and Senescence 3 The transition to reproductive development Reproduction and Senescence 4 Flower development Reproduction and Senescence 5 Male gametes Reproduction and Senescence 6 Female gametes (A) Megaspore mother cell at the tip of a young ovule primordium (B) Functional megaspore initiates embryo sac development (C) Mature ovule containing synergid cells, egg cell, central cell, and antipodal cells Reproduction and Senescence 7 Pollination and fertilization Genetic basis of self-incompatibility Reproduction and Senescence 8 Pollination and fertilization Growing pollen tube Reproduction and Senescence 9 Seed development Reproduction and Senescence 10 Senescence Ipomoea tricolor Welwitschia mirabilis Reproduction and Senescence 11 Senescence Reproduction and Senescence 12 Gene expression during senescence Groups of genes upregulated in senescing leaves and petals Reproduction and Senescence 13 Salvage of nutrients Nucleic acids Phosphate export Mitochondrion TCA cycle Reproduction and Senescence 14 Energy and metabolism Reproduction and Senescence 15 Pigment metabolism in senescence Chromoplast Chloroplast Gerontoplast Reproduction and Senescence 16 Environmental influences of senescence Cellular events during autumnal senescence in aspen Reproduction and Senescence 17 Programmed cell death AB, autophagic body AP, autophagosome Reproduction and Senescence 18 Programmed cell death Reproduction and Senescence 19 Programmed cell death The differentiation of tracheary elements Reproduction and Senescence 20 Environmental influences of PCD Cell death during the HR