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)

Abstract

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 of Thinopyrum 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 and ERCC1 expression (in wheat and Thinopyrum) and in GPX and GR activity (particularly in Thinopyrum). This is the first report of DNA photolyases being overexpressed under freezing stress. Older Thinopyrum had lower photolyase expression and less freezing‐induced overexpression of ERCC1. Younger Thinopyrum plants 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.

Transcriptome and Metabolome Analysis Revealed the Freezing Resistance Mechanism in 60-Year-Old Overwintering Camellia sinensis

“…Freezing stress in winter is the biggest obstacle to the survival of C. sinensis in midlatitude and high-latitude areas and an important factor causing crop yield reduction and even death [5][6][7][8]. When plants are subjected to freezing stress, photosynthesis will be inhibited and cell structure destroyed, resulting in oxidative damage, metabolic disorder, cell damage, and other phenomena [9][10][11]. Simultaneously, plants will express a large number of resistance genes and metabolites when subjected to freezing stress [12].…”

Cold-induced skin darkening does not protect amphibian larvae from UV-associated DNA damage

“…However, it is possible that cold-acclimation could induce the upregulation of CPD-photolyase following UVR exposure earlier than in warm-acclimated animals. To our knowledge there is no evidence of changes in the expression of DNA photorepair genes following thermal acclimation in animals, however acclimation to progressively colder temperatures significantly increased the upregulation of photolyase expression in wheatgrass (Jaikumar et al, 2020). While not direct evidence of an increase in photolyase gene expression, Drosophila selectively bred to cooler temperatures demonstrated upregulation of enzymes associated with nucleotide excision repair (Telonis-Scott et al, 2009).…”

“…While not direct evidence of an increase in photolyase gene expression, Drosophila selectively bred to cooler temperatures demonstrated upregulation of enzymes associated with nucleotide excision repair (Telonis-Scott et al, 2009). (Jaikumar et al, 2020).…”

Cold‐induced skin darkening does not protect amphibian larvae from UV‐associated DNA damage

“…However, it is possible that cold‐acclimation could induce the upregulation of CPD‐photolyase following UVR exposure earlier than in warm‐acclimated animals. To our knowledge there is no evidence of changes in the expression of DNA photorepair genes following thermal acclimation in animals, however, acclimation to progressively colder temperatures significantly increased the upregulation of photolyase expression in wheatgrass (Jaikumar et al, 2020). While not direct evidence of an increase in photolyase gene expression, Drosophila selectively bred to cooler temperatures demonstrated upregulation of enzymes associated with nucleotide excision repair (Telonis‐Scott et al, 2009).…”