Salicylic Acid: Biosynthesis, Metabolism and Physiological Role in Plants -- Effects of Salicylic Acid on the Bioproductivity of Plants -- Effect of Salicylic Acid on Solute Transport in Plants -- Role of Hormonal System in the Manifestation of Growth Promoting and Antistress Action of Salicylic Acid -- Role of Salicylic Acid in the Induction of Abiotic Stress Tolerance -- The Role of Salicylates in RHIZOBIUM-Legume Symbiosis and Abiotic Stresses in Higher Plants -- Stress and Antistress Effects of Salicylic Acid and Acetyl Salicylic Acid on Potato Culture Technology -- Salicylic Acid and Reactive Oxygen Species in the Activation of Stress Defense Genes -- The Interplay Between Salicylic Acid and Reactive Oxygen Species During Cell Death in Plants -- Salicylic Acid as a Defense-Related Plant Hormone -- Salicylic Acid and Local Resistance to Pathogens -- Salicylic Acid in Plant Disease Resistance -- Transcriptomic Analysis of Salicylic Acid-Responsive Genes in Tobacco By-2 Cells. Phytohormones are very much involved in directing plant growth, in a coordinated fashion in association with metabolism that provides energy and the building blocks to develop the form that we recognize as plant. Out of the recognized hormones, attention has largely been focused on Auxins, Gibberellins, Cytokinins, Abscisic acid, Ethylene and more recently to Brassinosteroids. However, this book provides information about a natural chemical, Salicylic Acid, that could be raised to the status of the above phytohormones because it has significant impact on various aspects of plant life. Salicylic acid (SA) was first discovered as a major component in the extracts from Salix (willow) whose bark from ancient time, was used as an anti-inflammatory drug. This acid (SA) is a phenol, ubiquitous in plants generating a significant impact on plant growth and development, photosynthesis, transpiration, ion uptake and transport and also induces specific changes in leaf anatomy and chloroplast structure. SA is recognized as an endogenous signal, mediating in plant defence, against pathogens. This book includes contributions made by various experts, spread over the world.