| Abstract Detail
Salinity Boyko, Oleksandr [1], Kovalchuk, Igor [2]. Immediate and transgenerational changes in plant genome stability triggered by salt stress. The influence of salt stress on genome stability was analyzed using transgenic A. thaliana plants. Plants were grown on MS media supplemented with NaCl for 3 weeks and then propagated into two subsequent generations. The genotoxic influence of salt stress on somatic tissues was reflected by an increase of DNA double strand breaks (DSBs) level, induction of homologous recombination rate (RR) and elevated transcription of AtRad51. Transgenerational effect of salt was reflected by significant increase in spontaneous RR in the immediate progeny grown under control conditions. The induction of RR was consistent with increase of AtRad51 and decrease of AtKu70 transcriptional activity. Importantly, the number of DNA DSBs was comparable between all progenies in both generations. Finally, the first progeny of salt-treated plants developed elevated tolerance to salt and MMS stresses. These changes were substantially reduced, when plants were propagated into the second generation without stress suggesting the possible epigenetic mechanisms behind this phenomenon. Indeed, the significant global genome hypermethylation was found in the first progeny of plants exposed to the low amounts of salt. This notion was supported by sequence-specific methylation analysis that revealed significantly higher methylation of 5’ UTR of AtAct2 gene. In contrast, the methylation pattern on recombination reporter gene was unaffected and comparable between progenies. Similarly, the difference in methylation diminished, when plants were propagated into the next generation without stress. Our data suggest that exposure to salt results in both, somatic and meiotic response and triggers transient changes in the genome stability, methylation and stress tolerance.
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1 - University of Lethbridge, Biological Sciences, HH129 Hepler Hall, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
2 - University of Lethbridge, Biological Sciences
Keywords:
salt stress
Transgenerational effects
methylation
homologous recombination
genome stability.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P07003
Abstract ID:252 |
