Explain : The direction of transport in plants.

Explanation

The direction of transport in plants is also important.
In rooted plants, transport in xylem (of water and minerals) is essentially unidirectional from roots to the stems.
But Organic and mineral nutrients however, undergo multidirectional transport. Organic compounds synthesised in the photosynthetic leaves are exported to all other parts of the plant including storage organs. From the storage organs they are later reexported.
The mineral nutrients are taken up by the roots and transported upwards into the stem, leaves and the growing regions.
When any plant part undergoes senescence, nutrients may be withdrawn from such regions and moved to the growing parts.
Hormones or plant growth regulators and other chemical stimuli are also transported, though in very small amounts.
Sometimes in a strictly polarised or unidirectional manner from where they are synthesised to other parts.
Hence, in a flowering plant there is a complex traffic of compounds (but probably very orderly) moving in different directions, each organ receiving some substances and giving out some others.