Variações anatômicas, estruturais e plasticidade fenotípica em duas regiões foliares ao longo da roseta de Aechmea distichantha Lem. (Bromeliaceae)

Abstract

Species of tank-dependent bromeliad usually have a reduced root system and thus, in addition to the photosynthetic activity, the leaves absorb water and nutrients that accumulate in the tank. It is expected that structural variations in the foliar tissues, due to different positions in the rosette, are related to the capacity to absorb and store water, and help in the physiological characterization of Aechmea distichantha Lem. Anatomical analyzes were performed on apex and leaf base samples occupying different positions along the rosette of A. distichantha. The analysis of phenotypic plasticity to evaluate the amplitude of the structural variations was done using histometry data. The cell wall structure was evaluated by immunocytochemistry assays using monoclonal antibodies. From the analyzes carried out, it was possible to verify that the leaves of A. distichantha present structural variations of the cell wall and phenotypic plasticity according to the analyzed leaf region and the position of the leaf in the rosette, the aquifer parenchyma being the most plastic tissue. The basal region of the leaves, mainly of the internal ones, presents / displays greater amount of parenchyma aquifer and pectin with high methyl esterification of the wall that facilitates the absorption of water in the initial stages of development. The apical region of the outer leaves in the rosette is more specialized for the photosynthetic activity, and presents less amount of aquifer parenchyma and more rigid cellular walls. Thus, from this work, it is noted that A. distichantha presents a structural and functional gradient both in the different regions of the leaf, and in leaves occupying different positions in the rosette.