Loss and re-establishment of desiccation tolerance in the germinated seeds of Sesbania virgata (Cav.) (Pers.)

Abstract

This research aimed to investigate the cellular alterations during the loss and reestablishment of desiccation tolerance (DT) in germinated Sesbania virgata seeds. The loss of DT was characterized in germinated seeds with increasing radicle lengths (1, 2, 3, 4 and 5 mm) when subjected to dehydration in silica gel, followed by rehydration. To re-establish DT, the germinated seeds were incubated for 72h in polyethylene glycol (PEG, −2.04 MPa) with or without ABA (100 μM) before dehydration in silica gel. Cell viability was assessed by seedling survival, and DNA integrity was evaluated by gel electrophoresis. Seeds with 1 mm radicle length survived dehydration to the original moisture content (MC) of the dry seed (approximately 10%). PEG treatment was able to re-establish DT, at least partially, with 2, 3 and 4 mm but not in 5 mm radicle lengths. Germinated seeds treated with PEG+ABA performed better than those treated only with PEG, and DT was re-established even in germinated seeds with a 5 mm radicle length. Among the PEG-treated germinated seeds dehydrated to 10% MC, DNA integrity was maintained only in those with a 1 mm radicle length.