They are rich in lipids, proteins and carbohydrates, and are sought after by various arthropods and ants, that carry out vigorous protection of the plant against herbivores, thus functioning as a biotic defence.
[2] Cells or tissues that offer food rewards to arthropods are commonplace in the plant world and are an important way of establishing symbiotic relationships.
[3] The simultaneous presence of pearl bodies, ant domatia and extrafloral nectaries, suggest a facultative plant-ant mutualism.
It also appears possible that the predatory mite Euseius sojaensis uses the pearl bodies as an alternative food source.
[8] A study by Deborah K Letourneau in 1983 found that the ants were so sated by the plant's pearl bodies that more than half the insect eggs they encountered while patrolling were dropped to the ground.
Food bodies of
Cissus verticillata
. (A–C) Ontogenesis of the food bodies. In (A), the initial stage of differentiation of these structures can be seen, and the first divisions of the subjacent tissues can be observed (arrow). (D) Detail of a mature food body, note the large volumes of the internal cells and the presence of plates of pectic compounds in the protoplast of the epidermal cells (arrows). (E) Apical portion of a branch with an ant patrolling a twig (arrow). (F) Ant (Crematogaster sp.) carrying a food body
Scanning electron microscopy images of
Cissus verticillata
food bodies. (A) Locality where food bodies are formed on the stem; note the depression in which the FBs are formed in the midst of the papilose epidermal cells. (B) Food bodies in the nodal region of the stem. (C) Food body in the nodal region, partially protected by the stipule. Inset: detail of the epidermal cells of a food body; note the absence of any pores or ruptured areas of the cuticle. (D) Food body on a leaf, detail of the distal portion, demonstrating a stoma (arrow)
