Department of Plant Breeding, Physiology and Seed Science, University of Agriculture in Kraków, Podłużna 3, 30-239 Kraków, Poland.
Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Jagiellońska 28, 40-032 Katowice, Poland.
Int J Mol Sci. 2021 Jan 21;22(3):1057. doi: 10.3390/ijms22031057.
Mechanisms involved in the de-acclimation of herbaceous plants caused by warm periods during winter are poorly understood. This study identifies the genes associated with this mechanism in winter barley. Seedlings of eight accessions (four tolerant and four susceptible to de-acclimation cultivars and advanced breeding lines) were cold acclimated for three weeks and de-acclimated at 12 °C/5 °C (day/night) for one week. We performed differential expression analysis using RNA sequencing. In addition, reverse-transcription quantitative real-time PCR and enzyme activity analyses were used to investigate changes in the expression of selected genes. The number of transcripts with accumulation level changed in opposite directions during acclimation and de-acclimation was much lower than the number of transcripts with level changed exclusively during one of these processes. The de-acclimation-susceptible accessions showed changes in the expression of a higher number of functionally diverse genes during de-acclimation. Transcripts associated with stress response, especially oxidoreductases, were the most abundant in this group. The results provide novel evidence for the distinct molecular regulation of cold acclimation and de-acclimation. Upregulation of genes controlling developmental changes, typical for spring de-acclimation, was not observed during mid-winter de-acclimation. Mid-winter de-acclimation seems to be perceived as an opportunity to regenerate after stress. Unfortunately, it is competitive to remain in the cold-acclimated state. This study shows that the response to mid-winter de-acclimation is far more expansive in de-acclimation-susceptible cultivars, suggesting that a reduced response to the rising temperature is crucial for de-acclimation tolerance.
冬季暖期导致草本植物去驯化的机制尚不清楚。本研究鉴定了冬大麦中与这一机制相关的基因。将 8 个品系（4 个对去驯化有耐受性，4 个对去驯化有敏感性的品种和先进的育种系）的幼苗在 3 周内进行冷驯化，然后在 12°C/5°C（白天/夜间）下进行 1 周的去驯化。我们使用 RNA 测序进行差异表达分析。此外，还使用反转录定量实时 PCR 和酶活性分析来研究选定基因表达的变化。在驯化和去驯化过程中，积累水平变化方向相反的转录物数量远低于仅在其中一个过程中水平变化的转录物数量。在去驯化敏感的品系中，在去驯化过程中，大量功能多样的基因表达发生变化。与应激反应相关的转录物，特别是氧化还原酶，在这个群体中最为丰富。研究结果为冷驯化和去驯化的不同分子调控提供了新的证据。在去驯化过程中，未观察到控制发育变化的基因的上调，这是春季去驯化的典型特征。在冬中去驯化过程中，似乎将其视为应激后再生的机会。不幸的是，保持在冷驯化状态是有竞争力的。本研究表明，在去驯化敏感的品种中，对冬中去驯化的反应要广泛得多，这表明对温度升高的反应减弱对于去驯化耐受性至关重要。
