Oxidative stress and ABA dynamics modulate dormancy and longevity of stored Caryocar brasiliense (Caryocaraceae) seeds
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Universidade Federal de Minas Gerais
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Artigo de periódico
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The interactions between oxidative stress and ABA dynamics constitute the main mechanisms controlling seed longevity and germination. However, little is known, about this subject in terms of tropical species. We evaluated the relationships between oxidative stress and ABA dynamics, and the dormancy and longevity of Caryocar brasiliense seeds, a fruit tree endemic to the Brazilian Cerrado. Freshly dispersed pyrenes (endocarp-enveloped seeds) were stored at room temperature and monitored for one year for germination, mortality, oxidative stress (H2O2 and MDA concentrations, and SOD, APX, and CAT activities), and ABA dynamics (ABA1, NCED4, NCED9 expression and hormone quantification). Newly dispersed seeds have high water contents, pronounced dormancy (related to the synthesis and accumulation of ABA), and tolerance to deterioration (low levels of oxidative stress). Seed water content becomes reduced and oxidative stress increases after between 40 and 60 days of storage, which lead to reductions in ABA synthesis and accumulation and the relief of dormancy. After this period, limitations of the control of oxidative stress lead to gradual reductions of the synthesis and accumulation of ABA, resulting in seed mortality. Interactions between oxidative stress control and ABA dynamics in C. brasiliense seeds during the second and third months of storage result in optimal seed quality, characterized by high germination rates.
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Pequi, Estresse oxidativo, Sementes - Dormência, Germinação, Fenologia
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https://link.springer.com/article/10.1007/s00344-024-11592-5