Potato more than onion, but both have some.
potato stores the starch in its root.
A potato stores its "food"mostly as starch in a tuber.
The part of the potato that we eat is a root, in which the potato plant has stored nutrients for its own use. Starch is a convenient nutrient with which to store calories that the plant can use to grow. We, of course, can also use starch for our own purposes.
The major purpose of a potato cell is for storing starch. Potatoes are underground stems that store energy reserves in the form of starch, allowing the plant to survive and grow during periods when photosynthesis is not actively occurring.
Storage food for seeds and varietals. Potatoes store all that starch in their trbers because the eyes of the potato are the progeny of the potato.
The potato does not store sugar because there is no sugar in it. The plant has starch in it which is then turned into "sugar" when it is eaten and digested. -when starch is digested, it turns to glucose. The organelle holding the startch grains are called leucoplasts.
Potato tuber cells have leucoplasts, which are specialized organelles that store starch. Leucoplasts also help in the synthesis and storage of other macromolecules such as lipids and proteins. These organelles are responsible for the accumulation of carbohydrates in the form of starch in the potato tubers.
Potatoes store their starch in their underground tubers, which are swollen underground stems. Starch is the primary energy reserve of the plant that is stored in these tubers to support growth and development.
Potatoes store their energy in the form of starch, which is a complex carbohydrate made up of glucose units. Starch serves as a long-term energy reserve for the potato plant.
Starch is a way of storing chemical energy for laster use; like freezing fuel into solid pieces which can be thawed and burnt or used in vehicles later on.
Potato is composite of relatively high amount of starch and sugar. Longer you store potato or more mature the potato gets, the starch are converted into sugar. Potato peel contains very trace amount of protein.
Amyloplasts are used for the synthesis and storage of starch. Proteins are usually stored in the Golgi Apparatus. As for the plants oils, that is different depending on the plant.