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Due to the economic importance of wood production, species including Cedrela fissilis Vell. and Cariniana legalis (Mart.) Kuntze have been heavily exploited and are currently threatened with extinction. In addition, these species produce seeds with low viability when stored for long periods. In this work, the effect of storage time on seedling emergence and alterations in the levels of biomolecules such as carbohydrates, polyamines (PAs), and amino acids were analyzed in C. fissilis and C. legalis seeds. Seedling emergence and the emergence speed index were significantly reduced during seed storage in both species, with a greater reduction for C. legalis seeds. Sucrose was detected in both species, with the highest levels in C. fissilis seeds, whereas the monosaccharides glucose and fructose were detected only in C. legalis seeds. Higher levels of putrescine (Put) were observed in C. legalis seeds than in C. fissilis seeds. In contrast, C. fissilis seeds showed a significant increase in most of the amino acids analyzed. These results suggest that the presence of glucose and fructose, the higher level of Put, and the lower levels of amino acids observed in C. legalis seeds may be associated with greater reductions in vigor and seedling emergence compared with C. fissilis seeds. This is the first report showing these relationships among carbohydrates, PAs, and amino acids in these species and may be useful for further studies on seed conservation of timber species.

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Seed aging is a critical process during storage and plays an important role in maintaining seed vigor. The present study aimed to investigate the effects of seed storage on germination and the differential abundance of proteins associated with viability loss in Cariniana legalis (Mart.) O. Kuntze. Seeds were stored for 12 months at 6 °C in plastic bags. Analyses of germination were performed at time 0 (newly harvested seeds) and after 3, 6, and 12 months of storage. To identify differentially abundant proteins, two-dimensional electrophoresis was performed, followed by tandem mass spectrometric (MS/ MS) analysis. Germination, the germination speed index and the moisture content were significantly reduced during storage. Proteomic analysis revealed 50 differentially abundant proteins among the times analyzed; these proteins were classified into several functional classes related to the biological, metabolic, cellular, oxidation-reduction, carbohydrate metabolism, storage, aging, cell wall organization or biogenesis, response to stress and stimulus, and proteolysis categories. The correlation between seed aging and proteome changes suggests that specific proteins may be involved in the mechanisms underlying seed deterioration, including ferritin, seed maturation-like, 2,4-dienoyl-CoA reductase, 11S globulin, polygalacturonases, superoxide dismutase, heat shock proteins, and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Our data showed that increasing storage time significantly reduced germination and revealed the regulation of differentially abundant proteins, which may be related to the reduction in seed viability in C. legalis.

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