Like all plants, Toxicodendron radicans are primary producers that generated their own food.  With the components carbon dioxide, water, and sun light a plant is able to create sugar, oxygen, and water.  The sugar, in the form of sucrose is the plants energy source.  The oxygen is essential in respiration for organisms such as ourselves. 

Photosynthesis occurs in the chlorophyll of the leaves.  So how does water from the ground get up to the leaves and how does the sucrose in the leaves able to supplement the whole plant?  The simple answer is vascular tissue!  The vascular tissue responsible for the transportation of water is xylem and the vascular tissue responsible for the transportation of sucrose and other nutrients is ploem.

 

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Water enter the plant via the root hairs.  Once inside the plant it travels either by means of a symplast or apoplast pathway to the xylem.  There is higher water concentration in the roots than in the leaves so water is moving against the concentration gradient.  This low concentration is caused by the transpiration of some water by means of evaporation in the leaves.   As that water evaporates, water in the xylem will start moving into the leave, this causes a tension between the water molecules.  Since the water molecules are highly cohesive the bonds do not break under this tension.  So the water is literally pulled up the from the roots to the leaves.

In contrast to water being pulled up, the nutrients created from photosynthesis are pushed down the phloem.  The sugars travel from a high osmotic pressure area to a low osmotic pressure area.  The sugars are transported into the sieve tube (phloem) via active transport.  Water also enters the phloem by osmosis creating phloem sap.  The addition of water to the sieve tubes creates pressure that pushes the nutrients down the sieve tube to an area of the plant that needs it.  Think of the sugar transportation is often described as sources and sinks.  It is a fairly straightforward concept, the leaves are the sources and all other parts of the plant that use or store these sugars.

Water and nutrient transportation