Plant Physiology is a dynamic science which goes on adding knowledge to already characterized basic processes in plants. The past decade has witnessed an unprecedented progress in biological sciences with the advent of innovative technologiesviz. recombinant DNA techniques, omics approaches and advanced phenotyping platforms. These tools have helped to redefine many of the already accepted facts of plant life. The present publication will give an insight into the lesser known signals that can influence plant growth and development. Knowledge of plant physiological processes provides the base for research in cognate disciplines such as crop improvement, crop production and crop protection. With the impetus for clean cultivation, information provided in the book can motivate researchers in developing environment-friendly and non-chemical means of improving crop production and activate the innate ability of the plant to enhance their field performance.