Colleters in Apocynaceae are persistent or deciduous emergences, whose secretion surrounds and protects buds and developing organs. Histochemical studies have shown that colleters found at shoot apices mainly secrete mucilage; however, some of them may produce a heterogeneous secretion in that group. Although this variation is found in different subfamilies of Apocynaceae, only one study has shown the secretory process involved in the production of this complex exudate in one species of the family. This project aims to analyze and describe ultrastructurally the colleters of four species belonged to the different subfamilies of Brazilian Apocynaceae, comparing the similarities and differences in the production of the different compounds that constitute their secretion. The identification and sampling of the material will be held in state of São Paulo. For this analysis, the shoot apex and the second node visible at naked eye will be isolated, fixed and processed according to the usual techniques of transmission electron microscopy. To assist in the analysis of the secretory activity, cytochemical tests will also be performed. In addition, scanning electron microscopy will be performed for the micromorphological study of colleters. The relevant data will be recorded by electron micrographs and compared with the available literature.
News published in Agência FAPESP Newsletter about the scholarship: