Anatomy, ultrastructure and chemical composition of food bodies of Hovenia dulcis (Rhamnaceae).
OBJECTIVE
Food bodies (FBs) are structures that promote mutualism between plants and ants, which help protect them against herbivores. The present study aims to describe the anatomical organization, ultrastructure and chemical composition of the FBs in Hovenia dulcis, which represent the first structures of this type described in Rhamnaceae.


METHODS
Leaves in various stages of development were collected and fixed for examination under light, transmission and scanning electron microscopy. Samples of FBs were subjected to chemical analysis using thin-layer chromatography and nuclear magnetic resonance of (1)H and (13)C.


RESULTS
The FBs vary from globose to conical and are restricted to the abaxial leaf surface, having a mixed origin, including epidermis and parenchyma. The FB epidermis is uniseriate, slightly pilose and has a thin cuticle. The epidermal cells are vacuolated and pigments or food reserves are absent. The parenchyma cells of immature FBs have dense cytoplasm showing mitochondria, endoplasmic reticulum and plastids. Mature FB cells store oils, which are free in the cytosol and occupy a large portion of the cell lumen. In these cells the plastids accumulate starch.


CONCLUSIONS
The lipids present in FBs are glycerin esters characteristic of plant energy reserves. Ants were observed collecting these FBs, which allows us to infer that these structures mediate plant-ant interactions and can help protect the young plants against herbivores, as these structures are prevalent at this developmental stage.
Buono
Rafael Andrade
RA
Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 - Belo Horizonte, MG, Brasil.
de Oliveira
Alaíde Braga
AB
Paiva
Elder Antonio Sousa
EA
D000821:Animal Feed; D000818:Animals; D001000:Ants / Q000502:physiology; D002247:Carbon Isotopes; D002855:Chromatography, Thin Layer; D006790:Host-Parasite Interactions; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010935:Plant Diseases / Q000469:parasitology; D010936:Plant Extracts / Q000032:analysis; D018515:Plant Leaves / Q000033:anatomy & histology / Q000737:chemistry / Q000648:ultrastructure; D027823:Rhamnaceae / Q000033:anatomy & histology* / Q000737:chemistry / Q000648:ultrastructure*
D002247:Carbon Isotopes; D010936:Plant Extracts