Ozone priming enhanced low temperature tolerance of wheat (Triticum aestivum L.) based on physiological, biochemical and transcriptional analyses

Low temperature significantly inhibits plant growth in wheat (Triticum aestivum L.), prompting the exploration of effective strategies to mitigate low temperature stress. Several priming methods enhance low temperature stress tolerance; however, the role of ozone priming remains unclear in wheat. Here we found ozone priming alleviated low temperature stress in wheat. Transcriptome analysis showed that ozone priming positively modulated the 'photosynthesis-antenna proteins' pathway in wheat under low temperature. This was confirmed by the results of ozone-primed plants, which had higher trapped energy flux and electron transport flux per reaction, and less damage to chloroplasts than non-primed plants under low temperature. Ozone priming also mitigated the overstimulation of glutathione metabolism and induced the accumulation of total ascorbic acid and glutathione, as well as maintaining redox homeostasis in wheat under low temperature. Moreover, gene expressions and enzyme activities in glycolysis pathways were upregulated in ozone priming compared with non-priming after the low temperature stress. Furthermore, exogenous antibiotics significantly increased low temperature tolerance, which further proved that the inhibition of ribosome biogenesis by ozone priming was involved in low temperature tolerance in wheat. In conclusion, ozone priming enhanced wheat's low temperature tolerance through promoting light-harvesting capacity, redox homeostasis and carbohydrate metabolism, as well as inhibiting ribosome biogenesis.