Plant physiology is one chapter from the classical handbook of Strasburger (2008). According to him, plant physiology is the science which is connected to the material and energy exchange, growth and development, as well as movement of plant. Plant physiology is the science that studies plant function: what is going on in plants that accounts for their being alive (Salisbury and Ross, 1992). Another definition of plant physiology by Taiz and Zeiger (2010) is the study of plant function, encompassing the dynamic processes of growth, metabolism and reproduction in living plants. Nowadays these latter two handbooks are widely used in the European higher educational level.Plant physiology is overlapped with its related branch of knowledge: biochemistry, biophysics, and molecular biology. The basic knowledge of plant physiology, that is necessary for experts in agriculture, is presented in our lecture notes based on the content of the above mentioned three handbooks, complemented with Hopkins and Hüner’s (2009) manual. Uptake and transport of water and minerals are explained in general. The nutrient supply of plant is presented in details (essential elements, solute transport, and nutritional deficiencies). Most common processes of plant biochemistry and metabolism, such as photosynthesis, are highlighted. Plant growth and development is introduced with the characterization and commercial use of plant growth regulators (PGRS, plant hormones). The basic concepts of plant stress is complemented with the presentation of physiological mechanisms against different environmental stresses.