The plants have low energy needs, as they use relatively slow transport systems. Plant transport systems move energy from leaves and raw materials from roots to all their parts. The xylem (tissue) moves water and minerals obtained from the soil to all other parts of the plants. Means of Transport, Plant-Water Relations, Long Distance Transport of Water, Transpiration, Uptake and Transport of Mineral Nutrients, Phloem, Transport: Flow from Source to Sink. Plants obtain a variety of inorganic elements (ions) and salts from their surroundings, especially from water and soil. In higher plants, there is a vascular system comprising of xylem and phloem, responsible for translocation. Phloem is responsible for transport of food (primarily) sucrose from the source to the sink. The translocation in phloem is explained by the pressure-flow hypothesis.
The chapter provides a description of the physiological processes observed in flowering plants. The mineral nutrition of plants, photosynthesis, transport, respiration, and finally plant growth and development are discussed in molecular terms but in the context of cellular activities and even at the organism level. The relation of the physiological processes to the environment is also discussed wherever necessary.