This revised edition of the book on Plant Physiology has been significantly enhanced to provide students with comprehensive support for their studies and examinations. specific chapters have been expanded with new and relevant content. To ensure the book's relevance and utility for current examinations, questions from recent undergraduate examinations of various universities, as well as questions from recent UPSC examinations, have been incorporated throughout the text. With these additions and the increased emphasis on objective-type questions, it is our sincere hope that this book will continue to effectively serve its primary purpose: to facilitate a thorough understanding of the fundamental principles of Plant Physiology and to empower students to achieve maximum marks in their examinations.