Redução da sensibilidade à dessecação em sementes recalcitrantes de espécies nativas

Abstract

Sensitivity to desiccation is a condition present in the seeds of several forest species of economic and ecological importance, which makes their seeds not tolerate drying and storage. Thus, studies that seek strategies to maintain the viability of such seeds after being subjected to drying are necessary. An alternative for this purpose is the use of physiological conditioning with the use of solutions of known osmotic potential. Solutions such as polyethylene glycol (PEG), glycerol, as well as phytohormones such as abscisic acid (ABA) and salicylic acid (AS) have shown an important relationship with stress tolerance in seeds. Recent studies indicate the action of these substances at the molecular level, acting as inducers in gene expression and modifying the abundance of proteins that are related to the activation of antioxidant systems, allowing seeds that do not tolerate desiccation to remain viable for longer periods when stored. The objective of this work was to condition seeds of forest species with recalcitrant behavior, using seeds of Inga vera, Campomanesia velutina, Eugenia uniflora and Tapirira guianensis, using solutions of PEG, AS, sucrose, glycerol and combinations of AS+PEG that can increase tolerance to desiccation. The treated and dried Campomanesia velutina seeds were submitted to proteomic analysis, aiming to compare how the abundance of total and heat-resistant proteins can be modified in those seeds submitted to physiological conditioning. There was no difference in the electrophoretic pattern of this species. The responses were different according to the species, but in general, positive responses in maintaining the viability of the seeds after drying were obtained from the conditioning with sucrose, glycerol and combinations of PEG and AS.