In situ DNA fragmentation during the re-establishment of desiccation tolerance in germinated seeds of Cedrela fissilis Vell.

Abstract

Dehydration is a necessary procedure prior to exposing seeds to long term storage, but this is associated with metabolism-linked injury mediated by cell injury. In order to assess cellular alterations during re-establishment of desiccation tolerance (DT) in C. fissilis germinated seeds and their relation to DNA damage, we verified the occurrence of DNA fragmentation through the TUNEL test and its evidence through the cytological analyses. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. The moisture content changes during the reestablishment of the desiccation tolerance was accomplished. (DT)TdT-dUPT terminal nick-end labeling (TUNEL) was used to assess rates of cell death. TUNEL staining was performed using Click-iT-TUNEL Alexa Flour imaging assay. The TUNEL test showed a consistent DNA fragmentation in the 2 and 5 mm long radicles. Moreover, nuclear and chromosomal alterations were observed in the 5 mm meristematic root cell cycle, contributing to the identification of diagnostic markers of cell death.

Toxicogenetic effects are involved in the occurrence of imbibitional damage in soybean seeds

“…To the Acta Scientiarum. Agronomy, v. 44, e53555, 2022 best of our knowledge, cell maintenance and genome integrity are critically important to prevent mutation prior to the re-initiation of cell cycle activity in the embryonic meristems (Dresch, Masetto, & Scalon, 2015;Waterworth et al, 2015;Masetto & Faria, 2019).…”

“…It was universally accepted that the development of a multicellular organism, such as a plant, is directly related to the processes of cell division, growth, and differentiation (Harashima & Schnittger, 2010). Indeed, recent evidence shows that in early-imbibing seeds, damage to the embryo genome must be repaired prior to the initiation of cell division to minimize growth inhibition, mutation of genetic information (Waterworth et al, 2015), and passive cell death (Masetto & Faria, 2019). DNA damage is caused during replication processes, but also by various endogenous and exogenous factors under stressful conditions.…”