part Part I: Overview of Mutualistic Associations and Defense -- chapter 1 Introduction: Symbiosis, Defensive Mutualism, and Variations on the Theme / chapter 2 Defensive Mutualism and Grass Endophytes: Still Valid after All These Years? / chapter 3 Overview of Defensive Mutualism in the Marine Environment / part Part II: Prokaryotic Defensive Symbionts -- chapter 4 Microbial Symbionts for Defense and Competition among Ciliate Hosts / chapter 5 Bacterial Chemical Defenses of Marine Animal Hosts / chapter 6 Is the Vibrio fi scheri–Euprymna scolopes Symbiosis a Defensive Mutualism? / chapter 7 Entomopathogenic Nematode and Bacteria Mutualism / chapter 8 Interspecies Competition in a Bacteria–Nematode Mutualism / chapter 9 Defensive Symbionts in Aphids and Other Insects / chapter 10 Fungus-Growing Ant–Microbe Symbiosis: Using Microbes to Defend Benefi cial Associations within Symbiotic Communities / part Part III: Eukaryotic Defensive Symbionts -- chapter 11 Chemical Defense in Lichen Symbioses / chapter 12 Arbuscular Mycorrhizae as Defense against Pathogens / chapter 13 Evaluation of Mycorrhizal Symbioses as Defense in Extreme Environments / chapter 14 Effect of Arbuscular Mycorrhizal Symbiosis on Enhancement of Tolerance to Abiotic Stresses / chapter 15 Conifer Endophytes / chapter 16 Diversity and Ecological Roles of Clavicipitaceous Endophytes of Grasses / chapter 17 Contributions of Pharmaceutical Antibiotic and Secondary Metabolite Discovery to the Understanding of Microbial Defense and Antagonism / part Part IV: Fungal Endophyte as Moel System to Understand Defensive Mutualism -- chapter 18 Extensions to and Modulation of Defensive Mutualism in Grass Endophytes / chapter 19 Conceptual Model for the Analysis of Plant–Endophyte Symbiosis in Relation to Abiotic Stress / chapter 20 Habitat-Adapted Symbiosis as a Defense against Abiotic and Biotic Stresses / chapter 21 Insect Herbivory and Defensive Mutualisms between Plants and Fungi / chapter 22 Fungal Endophytes: Defensive Characteristics and Implications for Agricultural Applications / chapter 23 Endophytic Niche and Grass Defense