Ontogênese, estrutura e aspectos funcionais dos Tricomas glandulares de Adenocalymma magnificum MART. EX DC. E Bignonia aequinoctialis L. (Bignoniaceae)

Abstract

This study focused on the secretory structures of Adenocalymma magnificum and Bignonia aequinoctialis: their development, structure and secretory processes in both the vegetative axis and reproductive axis. Because glandular trichomes are characteristic structures of Bignonieae they become important diagnostic markers for the tribe in question. Several studies are turning their attention to the phylogeny, however it often becomes necessary to understand the evolutionary patterns of individual morphological features to complement evidence about the adaptive hypotheses. In the first chapter, we were interested in to know development and to study the function of pateliform glandular trichomes of Adenocalymma magnificum; the trichome originate from a single protodermic cell, is asynchronous and presents on both the vegetative and reproductive axes with, during this secretory fase they release sugar, lipids and phenolic compounds, by different metabolic pathways; the sugar, produced in the pre-nectar, is transported to the secretory cell by transfer cells present in trichome. In the second chapter, the study was only the capitate glandular trichome of A. magnificum, development and function of these structures. It occurs on the inner surface of the calyx and first develop various peduncle cells and then the apical cell divides in anticlinal form, forming the head cells; the secretion of this capitates trichome is lipophilic, being produced by three organelles, including mitochondria. The third chapter described the ontogenesis of peltate and patelliform glandular trichomes, distributed on the vegetative axes and calyx of Bignonia aequinoctialis; all the trichomes originate from a single cell and the development is asynchronous; The secretion of the peltate glandular trichomes consists of lipophilic substances and the patelliform consists of both nectar and phenolic compounds. The sugar secretion in the patelliform trichomes, from both species, allowed a brief discussion about an important role in insect-plant interactions, they serve as food for ants that reciprocate by protecting the plant (generally). We can conclude that functional and morphological information about trichomes are importante in this group of plants.