Root System
The root system is usually underground in the soil but can also grow above ground or above water. The first root that grows from a seed is called the radicle which has four main functions: to absorb water and other nutrients, to support and anchor the plant, to store food and nutrients and vegetative reproduction. In response to the concentration of nutrients, the roots synthesize cytokinin which is a plant growth substance that promotes cell division in the root and shoot. This acts as a signal as how fast the shoot can grow. The roots of most vascular plant species enter into symbosis with certain fungi to form mycorrhizae which is a symbiotic association between fungus and roots. A large range of other organisms including bacteria are also closely associated with roots. |
Shoot System
The shoot system includes the stem, appendages, leaves, buds and flowers. The shoot grows upward. In the spring there can be new plant growth from the ground which are herbaceous plants or there is new flower growth on woody plants. Stems are integral parts of shoots because they provide an axis for buds fruits and leaves. Young shoots are often eaten by animals because the new fibers in the new growth have not completed secondary growth cell wall development and therefore the stems are softer and easier for animals to chew. A secondary wall is a hard and tough structure.