Sulfur is a nutrient essential for plant growth. Sulfates are the primary source of sulfur for plants, which they take up from the rhizosphere. Gaseous sulfur dioxide is also absorbed by plants through the stomata and is converted into sulfite. All the inorganic sulfur absorbed by plants is assimilated by them by converting it into cysteine. This is again processed and changed into methionine. The secondary products containing sulfur have a characteristic smell and act as a defense mechanism for plants against herbivores, insects and other pathogens. These compounds also act as signalling molecules for fundamental cellular functions. From theories to research to practical applications, case studies related to all contemporary topics of relevance to this field have been included in this book. Also included herein is a detailed explanation of the various mechanisms and applications of sulfur metabolism in plant growth. This book is a vital tool for all researching or studying sulfur metabolism in plants as it gives incredible insights into emerging trends and concepts.