Phosphorous is used by the plant in energy transformations and in many of the conversion processes in which sugars are converted to hormones, protein, energy to grow new leaves and fruits. As such, it is found most concentrated in root tips and above-ground growing points, seed and fruiting organs. A deficiency of phosphorous results in stunting, accumulation of unused sugars, and conversion of these excess sugars to anthocyanin, the red pigment said to be typical of low phosphate levels. The formation of anthocyamin is associated with accumulation of sugars in plant tissues. Any environmental factor such as high light intensity, low temperature, drought, low nitrogen supply, or low phosphorous supply, which favors as increase in the sugar content of a given plant tissue, favors the synthesis of anthocyamins in that tissue. Phosphorous is present in all living cells. It is utilized by plants to form nucleic acids (DNA and RNA). It is used in storage and transfer of energy through energy-rich linkages (ATP and ADP).
Phosphorous is easily redistributed in plants from one organ to another and is lost from older leaves, accumulating in growing points. As a result, defciency symptoms occur first in the more mature leaves.
In humans, phosphorous is essential for the building of sound bones and teeth, and for the assimilation of carbohydrates and fats. It is necessary for enzyme activation. Phosphorous acts as a buffer in blood and tissue.