6 Part IV: Physiological Aspects of Nucleotide Metabolism 12 Growth and Development 12.1 Introduction 12.2 Embryo Maturation 12.3 Germination 12.4 Organogenesis 12.5 Breaking Bud Dormancy 12.6 Fruit Ripening 12.7 Storage Organ Development and Sprouting 12.8 Suspension-Cultured Cells 12.9 Molecular Studies 12.10 Summary References 13 Environmental Factors and Nucleotide Metabolism 13.1 Introduction 13.2 Effect of Phosphate on Nucleotide Metabolism 13.3 Effect of Salts on Nucleotide Metabolism 13.4 Effect of Water Stress 13.5 Effect of Wound Stress 13.6 Effect of Iron Deficiency 13.7 Effect of Light 13.8 Summary References
7 Part V: Purine Alkaloids 14 Occurrence of Purine Alkaloids 14.1 Introduction 14.2 Chemical Structure of Purine Alkaloids 14.3 Occurrence of Purine Alkaloids in Plants 14.4 Summary References 15 Biosynthesis of Purine Alkaloids 15.1 Introduction 15.2 A Brief History of Caffeine Biosynthesis Research 15.3 Caffeine Biosynthesis Pathway 15.4 Genes and Proteins of Caffeine Synthase Family 15.5 Xanthosine Biosynthesis from Purine Nucleotides 15.6 Summary References 16 Physiological and Ecological Aspects of Purine Alkaloid Biosynthesis 16.1 Introduction 16.2 Physiology of Caffeine Biosynthesis 16.3 Subcellular Localization of Caffeine Biosynthesis 16.4 Regulation of Caffeine Biosynthesis 16.5 Ecological Roles of Caffeine 16.6 Summary References 17 Metabolism of Purine Alkaloids and Biotechnology 17.1 Introduction 17.2 Metabolism of Purine Alkaloids 17.3 Diversity of Purine Alkaloid Metabolism in Plants 17.4 Biotechnology of Purine Alkaloids 17.5 Caffeine-Producing Transgenic Plants 17.6 Summary References
8 Part VI: Pyridine Nucleotide Metabolism 18 Pyridine (Nicotinamide Adenine) Nucleotide Biosynthesis De Novo 18.1 Introduction 18.2 Two Distinct Pathways of De Novo Nicotinate Mononucleotide Biosynthesis 18.3 The Outline of the De Novo Pathway of NAD Biosynthesis in Plants 18.4 Enzymes Involved in De Novo NAD Synthesis in Plants 18.5 Summary References 19 Pyridine Nucleotide Cycle 19.1 Introduction 19.2 Pyridine Nucleotide Cycle 19.3 Catabolism of NAD 19.4 Enzymes Involved in NAD Catabolism 19.5 Salvage of Nicotinamide and Nicotinate 19.6 Summary References