Melatonin (N-acetyl-5-methoxytryptamine) is a widely studied biomolecule, and its function has been investigated in bacteria, mammals, birds, amphibians, reptiles, fish and plants. Melatonin research in plants the last five years has attained an exponential growth phase and the number of publications related to phytomelatonin has significantly increased in present times. All this research is directed towards establishing multifarious roles of melatonin in plants, including the promotion of seed germination and seedling growth, influencing plant development and senescence, alteration of flowering and fruiting time and grain yield, modulating circadian rhythms, improving resistance against biotic stress as well as tolerance to abiotic stress, reducing oxidative stress, and stimulating plant immune response. However, to date, an exhaustive book, solely and exclusively dedicated to melatonin research on various aspects of plant biology, has not been published by any renowned publisher or is available in the market. Keeping all these facts in mind, this book aims to compile the most recent developments in the arena of melatonin-mediated regulation of plant physiology under optimal and sub-optimal conditions. This book will initiate and introduce the readers to the state-of-the-art developments and trends in this field of study and will largely cater to the scientific need of scientists engaged in melatonin research across the globe. The book will be unique of its kind and will draw the attention of scientific and research communities engaged in the field of melatonin research.The key features of this book:• Authors will address the topics which would provide advances in the understanding of diverse functions of melatonin in plants, encompassing almost all the aspects that have been investigated so far.• Integrate the overall mechanistic function of melatonin, genomics and proteomics tools, and genetic engineering to manipulate endogenous mela