Part I. Fungal Symbiosis -- Current Status-Enlightens in Its Biology and Omics Approach on Arbuscular Mycorrhizal Community -- An Insight through Root-Endophytic-Mutualistic Association in Improving Crop Productivity and Sustainability -- Interaction Between Root Endophytes and Plants: Their Bioactive Products and Significant Functions -- Unravelling the Role of Endophytes in Micronutrient Uptake and Enhanced Crop Productivity -- Dual and Tripartite Symbiosis of Invasive Woody Plants -- Eco-friendly Association of Plants and Actinomycetes -- The Arbuscular Mycorrhizal Symbiosis of Trees: Structure, Function, and Regulating Factors -- Effectiveness of Arbuscular Mycorrhizas in Improving Carob Culture in the Mediterranean Regions -- Leaf Endophytes and Their Bioactive Compounds -- Role of Endophytic Fungus Piriformospora indica in Nutrient Acquisition and Plant Health -- The Role of Symbiotic Fungi in Nutri-Farms -- Part II. Bacterial Symbiosis -- Understanding the Evolution of Plant Growth-Promoting Rhizobacteria -- Rhizobia-Legume Symbiosis During Environmental Stress -- Archaeal Symbiosis for Plant Health and Soil Fertility -- Microbial Symbionts of Aquatic Plants -- Rhizobium Presence and Functions in Microbiomes of Non-leguminous Plants -- Part III. Insect-Fungus Mutualism -- Symbiotic Harmony Between Insects and Fungi: A Mutualistic Approach -- Panorama of Metarhizium: Host Interaction and Its Uses in Biocontrol and Plant Growth Promotion -- Arbuscular Mycorrhizal Fungi: Potential Plant Protective Agent Against Herbivorous Insect and Its Importance in Sustainable Agriculture -- Eradication of Malaria by the Mutualistic Interaction Between Wickerhamomyces anomalus and Anopheles sp -- Part IV. Microbial Symbiosis in Disease and Stress Management -- Halophyte-Endophyte Interactions: Linking Microbiome Community Distribution and Functionality to Salinity -- Root Endophytic Microbes and Their Potential Applications in Crop Disease Management -- Do Mycorrhizal Fungi Enable Plants to Cope with Abiotic Stresses by Overcoming the Detrimental Effects of Salinity and Improving Drought Tolerance? -- Combined Use of Beneficial Bacteria and Arbuscular Mycorrhizal Fungi for the Biocontrol of Plant Cryptogamic Diseases: Evidence, Methodology, and Limits -- Remediation of Toxic Metal-Contaminated Soil and Its Revitalisation with Arbuscular Mycorrhizal Fungi.