Discontinuous hydration in seeds of Sarcomphalus joazeiro Mart. Hauenschild (Rhamnaceae) improve seedling tolerance to water deficit

da Costa Oliveira, Maria Fernanda and Ciriaco da Silva, Elizamar and Alves Vieira, Evandro and Resende Silva, Kleber and Moreira Lobo, Ana and Alves da Silva, Emerson (2024) Discontinuous hydration in seeds of Sarcomphalus joazeiro Mart. Hauenschild (Rhamnaceae) improve seedling tolerance to water deficit. New Forests. ISSN 0169-4286

Text (Manuscript_accepted)
Manuscript_accepted_merged.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (1MB)

Abstract

Water is an essential abiotic factor for seed imbibition process. Seeds of several Caatinga species have a physiological strategy known as seed hydration memory to mitigate the effects of irregular rainfall patterns in this environment. However, the mechanisms behind are not well understood. Therefore, our study aimed to evaluate the occurrence of water memory in Sarcomphalus joazeiro seeds through ecophysiological, biochemical and anatomical analyzes. The seeds were subjected to different cycles (0, 1, 2, and 3) of hydration (12 h) and dehydration (48 h)-HD, or continuous hydration (CH) for 183 h. The seedlings obtained of these seeds were subjected to different water suspension cycles. Our results showed that seeds subjected to HD cycles had greater germinability, higher emergence speed index, lower T50 values, and accumulated higher proline content. Seedlings from the 0, 1, and 2 seed HD cycles showed decreased net carbon assimilation (A) only when subjected to severe stress after 21 days of water deficit compared to the daily irrigated plants. While in seeds exposed to 3-HD cycles after 21 days of water deficit A did not change compared to control. Our results evidenced that seeds subjected to 3-HD cycles conferred the plants a greater tolerance to water deficit, proving the existence of seed hydration memory in Sarcomphalus joazeiro.