This book offers a comprehensive exploration of plant neurotransmitters, focusing on their roles in plant development and agricultural applications. Section 1 delves into the biosynthesis, regulation, and signaling mechanisms of key neurotransmitters such as serotonin, dopamine, GABA, acetylcholine, and melatonin. It examines how these molecules influence various developmental processes including morphogenesis, root architecture, senescence, photosynthesis, nutrient dynamics, flowering, and seed development. Section 2 shifts to practical applications, highlighting how plant neurotransmitters help plants cope with abiotic and biotic stresses, improve nutrient use efficiency, and enhance crop yields. It discusses the potential and limitations of externally applying these compounds in agriculture, their role in rhizospheric and cross-kingdom signaling, and their promise as eco-friendly tools for food security. The book also introduces advanced approaches like multi-omics to better understand and harness these molecules. Finally, it addresses the challenges of integrating plant neurotransmitters into mainstream agricultural practices. Together, these sections provide a timely and in-depth resource for researchers, agronomists, and students interested in plant biology and sustainable agriculture.