ABA-regulated ploidy-related genes and non-structural carbon accumulation may underlie cold tolerance in tetraploid Fragaria moupinensis

Abstract

Low temperature is a common environmental stress factor. Polyploidy has often been considered to confer adaptation to cold stress in plants. However, the mechanisms by which abscisic acid (ABA) regulates non-structural carbon (NSC) in polyploids, yielding an advantage in various ecological contexts, are largely unknown. Here, we have compared transcriptomic data from two Fragaria species in response to cold stress to assess ABA-regulated cold tolerance mechanisms. Endogenous ABA and proline content as well as superoxide dismutase (SOD) and peroxidase activities of tetraploid Fragaria moupinensis were higher than those of diploid F.pentaphylla under control conditions. Cold stress significantly increased proline content and SOD activity in both Fragaria species. We found that accumulation of soluble sugar and non-structural carbon under cold stress are key factors underlying cold resistance in F. moupinensis. Under cold stress, compared to F. pentaphylla, ABA-related genes exhibited significant differences in regulation. In contrast, in F. moupinensis, some anti-oxidation genes and transcription factors were up-regulated relative to F. pentaphylla under cold stress. In total, 1274 genes were associated with ABA. Our results revealed up-regulated ABA-related genes, anti-oxidant genes, and transcription factors and the consequent accumulation of NSC to likely underlie cold tolerance in tetraploid F. moupinensis.