Semester of Graduation
Fall 2025
Degree
Master of Science (MS)
Department
Biological Sciences
Document Type
Thesis
Abstract
Seeds of salt-sensitive plants germinate under high salinity but fail to maintain growth following germination. Typically, salt stress leads to seedling lethality in crops. Halophyte seeds have evolved to avoid this fate in saline soils. Seeds of the halophyte Schrenkiella parvula remain dormant under high salinity but rapidly germinate once external salt concentration is reduced. In addition to salts like NaCl and KCl, osmotic stress inducing agents, including mannitol can inhibit germination by lowering external water potential. The transient state of germination inhibition can be reversed by transferring the seeds from a high salt to control medium. I aimed to identify the transcriptional and hormonal adjustments in response to high sodium induced seed germination inhibition as well as how the seed rapidly progresses germination when salt stress is removed compared. I compared these changes to seeds germinated without an interruption on a standard growth medium without added sodium. Time-dependent transcriptome profiling revealed that transcripts which code for oleosin and late-embryogenesis proteins were enriched in ungerminated seeds, while transcripts associated with photosynthesis, aquaporins, and cell-wall remodeling were induced in germinating seeds. Abscisic acid (ABA) remained high in dormant seeds or ungerminated seeds in the control medium compared to the levels observed in germinated seeds. In contrast Gibberellic acid remained at constant levels between imbibed and germinated seeds. Together, this study proposes a model for halophytes in which quiescence is maintained in salt-plated seeds by high salinity induced osmosensing and lowering the external salinity triggers coordinated transcriptional responses for cell wall remodeling, negative regulation ABA, and salt and water transport to rapidly progress to a germinated seedling.
Date
11-11-2025
Recommended Citation
Garcia, Jason R., "DECODING TRANSCRIPTOMIC CHANGES DURING SALT-INDUCED DORMANCY AND ITS RAPID REVERAL IN A SALT-ADAPTED EXTREMOPHYTE" (2025). LSU Master's Theses. 6265.
https://repository.lsu.edu/gradschool_theses/6265
Committee Chair
Dassanayake, Maheshi.