This thoroughly revised and updated edition provides an accessible overview of the rapidly advancing field of plant physiology. Key topics covered include absorption of water, ascent of sap, transpiration, mineral nutrition, fat metabolism, enzymes and plant hormones. Separate chapters are included on photosynthesis, respiration and nitrogen metabolism, and emphasis is placed on their contribution to food security, climate resilient farming (or climate-smart agriculture) and sustainable development. There is also a chapter on the seminal contributions of plant physiologists. Supported by the inclusion of laboratory experimental exercises and solved numerical problems, the text emphasises the conceptual framework, for example, in coverage of topics such as thermodynamics, water potential gradients and energy transformation during metabolic processes, water use efficiency (WUE) and nitrogen use efficiency (NUE). Bringing together the theoretical and practical details, this text is accessible, self-contained and student-friendly.