COLÉTERES FOLIARES EM Clusia burchelli Engl. e Clusia criuva Cambess. subsp. criuva (Clusiaceae)

Abstract

Secretions of great economic and ecological importance are widely studied in Clusiaceae, however reports of secretory structures known as colleters are scarce for the group. Thus, we aim to characterize the leaf colleters of Clusia created Cambess. subsp. criuva and Clusia burchelli Engl., to identify chemical compounds produced at different stages of leaf development and to identify the morphology of these structures. Leaves at different stages of development (meristems with leaf primordia, adult leaves and senescent leaves) were collected and processed according to usual techniques for light microscopy, including histochemical tests; scanning electron microscopy and transmission electron microscopy (Clusia burchelli). In both species, colleters occur on the adaxial surface of the leaves, in the region of insertion with the stem. They are avascularized, have a short peduncle, a multicellular head formed by a central axis of parenchymal cells and a secretory epidermis, being classified as standard type colleters. However, most Clusia burchelli colleters are extended from the base to the apex while others are cone-shaped. In Clusia he created subsp. criuva, the colleters have a lacrimiform shape and a constriction in the apical portion. Histochemical tests showed the presence of polysaccharides, pectins, phenolic compounds and alkaloids in the secretion of colleters in the three stages of leaf development in both species. Proteins were evidenced in the secretion and in the cells of the secretory portion of Clusia created subsp. criuva. Clusia burchelli also found lipids in the secretion and drops of essential oil inside the secretory cells. The difference in the chemical composition of the secretion may be related to the environment where the species occur, Clusia burchelli being endemic to the cerrado and Clusia creating subsp. occurring in the Atlantic Forest or may be intrinsic characteristics of the species.