Biotechnological Potential of Ribosome Inactivating Proteins (RIPs) -- Cyanotoxins Cyclotides: Plant Defense Toxins -- Entomotoxic Plant Proteins: Molecules to Develop Genetically Modified Plants Potentially Resistant to Insect-Pests -- General Mechanisms of Plant Defense -- Locoweeds and Swainsonine -- Moonlighting Toxins: Ureases and Beyond -- Oleander Poisoning -- Phycotoxins Other Than Cyanotoxins -- Plant AB Toxins with Lectin Domains -- Plant Alkaloids: Main Features, Toxicity, and Mechanisms of Action -- Plant and Fungal Hallucinogens as Toxic and Therapeutic Agents -- Plant Compounds with Antiophidic Activities, Their Discovery History, and Current and Proposed Applications -- Plant Cyanogenic Glycosides -- Plant Toxins as Sources of Drugs -- Plants Toxic to Farm and Companion Animals -- Proteinaceous Plant Toxins with Antimicrobial and Antitumor Activities Ribosome-Inactivating Proteins: An Overview -- Suicidal Plant Poisoning -- The Role of Metal-Based Defenses in Plants -- Toxic but Exploitable Actions of Ribosome-Inactivating Proteins -- Toxic Chemicals from Invasive Alien Plants -- Toxic Nonprotein Amino Acids.