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Title: Nucleic acid damage and DNA repair are affected by freezing stress in annual wheat ( Triticum aestivum ) and by plant age and freezing in its perennial relative ( Thinopyrum intermedium )
PREMISE

Nucleic acid integrity can be compromised under many abiotic stresses. To date, however, few studies have considered whether nucleic acid damage and damage repair play a role in cold‐stress adaptation. A further insufficiently explored question concerns how age affects cold stress adaptation among mature perennials. As a plant ages, the optimal trade‐off between growth and stress tolerance may shift.

METHODS

Oxidative damage to RNA and expression of genes involved in DNA repair were compared in multiple mature cohorts ofThinopyrum intermedium(an emerging perennial cereal) and in wheat and barley under intermittent freezing stress and under nonfreezing conditions. Activity of glutathione peroxidase (GPX) and four other antioxidative enzymes was also measured under these conditions. DNA repair genes included photolyases involved in repairing ultraviolet‐induced damage and two genes involved in repairing oxidatively induced damage (ERCC1, RAD23).

RESULTS

Freezing stress was accompanied by large increases in photolyase expression andERCC1expression (in wheat andThinopyrum) and in GPX and GR activity (particularly inThinopyrum). This is the first report of DNA photolyases being overexpressed under freezing stress. OlderThinopyrumhad lower photolyase expression and less freezing‐induced overexpression ofERCC1. YoungerThinopyrumplants sustained more oxidative damage to RNA.

CONCLUSIONS

Overexpression of DNA repair genes is an important aspect of cold acclimation. When comparing adult cohorts, aging was associated with changes in the freezing stress response, but not with overall increases or decreases in stress tolerance.

 
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NSF-PAR ID:
10454680
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
American Journal of Botany
Volume:
107
Issue:
12
ISSN:
0002-9122
Page Range / eLocation ID:
p. 1693-1709
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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