Chapter 1:Overview of Plant Secondary Metabolites: Their Types, Classification, and Significance Tahmeena Khan, Kulsum Hashmi Chapter 2:Enzymatic and Regulatory Processes Involved in the Biosynthesis of Secondary Metabolites Sharfa Naaz, Ragib Husain, Vinay Kumar Singh, Mohammad Israil Ansari Chapter 3:Comprehensive Insights into Alkaloids: Their Functions, Roles, and Modern Utilization Saad Salhi, Noureddine Chaachouay, Abdelkarim El Djiri, Abdelkhalid Essamadi, Abdellatif Rahim Chapter 4:Terpenoids and their multi-functional roles in plant defense and ecology Sandeep K. Behera, Gayatri Talekar, Amit B. Verma, Fatima Z. Kamal, Nimisha Patel, Ahmad Ali, Hina Alim Chapter 5:Role of Phenolic Compounds in Antioxidant Protection and Plant Stress Resilience Fouzia Bashir, Jamal Akhtar Chapter 6:Flavonoids and Their Contributions to Biochemistry Biosynthetic Pathways and Ecological Interactions Nilofer, Abdul Mazeed, Mohammad Israil Ansari Chapter 7:Plant secondary metabolites in defence against herbivores and pathogens Al-kazafy Hassan Sabry, Zakaria Abdelhalim Attia Chapter 8:Secondary Metabolites as Key Mediators of Ecological Interactions Among Plants and Animals Shambhavi Tiwari, Jyotiraj Upadhyay, Shashi Pandey-Rai Chapter 9:Role of Plant Secondary Metabolites in Abiotic Stress Responses Ali Asger Bhojiya, Asha Ben Sharma Chapter 10:Understanding Plant Volatile Organic Compounds and Their Functions in Defence and Signaling Neha Prajapati, Deepanshi Jaiswal Chapter 11:Methods and Techniques for Extraction and Purification of Plant Secondary Metabolites Noureddine Chaachouay, Saad Salhi, Abdellatif Rahim, Abdelkhalid Essamadi Chapter 12:Secondary Metabolites as Natural Alternatives to Synthetic Pesticides in Sustainable Agriculture Jagriti Singh, Pajeb Saha, Sabitri Kumari, Mansi Singh Bisen, Shashi Pandey-Rai Chapter 13:Biotechnological Applications of Plant Secondary Metabolites in Crop Improvement Kulsum Hashmi, Tahmeena Khan Chapter 14:Role of Secondary Metabolites in Plant Tissue Culture and Regeneration Saumya Pandey Chapter 15:Metabolic Engineering of Secondary Metabolites for Improved Crop Protection and Yield Weria Weisany Chapter 16:Interactions Between Secondary Metabolites and Soil Microorganisms and Their Implications for Plant Health Tarek Alshaal, Atilla Kiss, Nevien Elhawat Chapter 17:Genomic Approaches to Understanding the Biosynthesis of Secondary Metabolites Debadrita Das, Archita Dey, Tarit Roychowdhury Chapter 18:Phytochemical Diversity in Agroecosystems and Its Implications for Organic Farming and Pest Management Neha Singh, Nisha Yadav, Shaili Srivastava Chapter 19:Environmental Stress and the Regulation of Secondary Metabolite Production in Plants Abdul Mazeed, Mohd. Mohasin, Nitish Kumar, Nilofer, Faria Fatima, Mohammad Israil Ansari Chapter 20:Secondary Metabolites in Agroforestry Systems and Their Contributions to Ecosystem Sustainability Sadia Abdullah, Mamoona Munir, Asad Ghulam Nabi, Bisma Javed, Wasim Akhtar, Mushtaq Ahmad, Sumreen Dawood, Maria Ameen.