Autophagy and its implications on the development of resiniferous canals in Anacardium humile A. St.-Hill. (Anacardiaceae)

Abstract

Autophagy is one of the main catabolic processes in eukaryotic cells, highly conserved, classified into macroautophagy and microautophagy, in addition to specific autophagy and megaautophagy (additional types). Although the role of autophagy in response to environmental stresses and normal plant developmental processes is relatively well known, its implications for the development of secretory systems remain poorly understood. Except for laticifers and nectaries of a few plant species, there is a large knowledge gap considering the morphological and functional diversity of secretory structures, as well as poorly studied taxonomic groups, especially those of tropical distribution. Secretory canals are sites for the production and storage of various substances, many of them for medicinal, pharmacological and industrial use, such as Anacardiaceae resin canals. Although microscopic studies focused on the mode of formation and initial development of secretory canals in representatives of this family point to signs of autophagy, autophagic processes have not been adequately explored or even mentioned. Using routine and advanced light and transmission electron microscopy methods, the aim of this study is to characterize the autophagic process during the development of resin canals in the vegetative axis of Anacardium humile A. St.-Hil., a subshrub representative of native Anacardiaceae from the Cerrado. The data will be discussed in the light of cell biology aiming to identify the type (s) of autophagy and understand its implications on the development of the secretory canals for the studied species, as well as contribute to deepen the discussions about the regulation of autophagy in natural conditions. (AU)