Zuther Ellen, Juszczak Ilona, Lee Yang Ping, Baier Margarete, Hincha Dirk K
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany.
FU Berlin, Institute of Biology, DCPS, Plant Physiology, Königin-Luise-Straße 12-16, 14195 Berlin, Germany.
Sci Rep. 2015 Jul 15;5:12199. doi: 10.1038/srep12199.
During low temperature exposure, Arabidopsis thaliana and many other plants from temperate climates increase in freezing tolerance in a process termed cold acclimation. However, the correct timing and rate of deacclimation, resulting in loss of freezing tolerance and initiation of growth is equally important for plant fitness and survival. While the molecular basis of cold acclimation has been investigated in detail, much less information is available about deacclimation. We have characterized the responses of 10 natural accessions of Arabidopsis thaliana that vary widely in their freezing tolerance, to deacclimation conditions. Sugar, proline and transcript levels declined sharply over three days in all accessions after transfer of cold acclimated plants to ambient temperatures, while freezing tolerance only declined in tolerant accessions. Correlations between freezing tolerance and the expression levels of COR genes and the content of glucose, fructose and sucrose, as well as many correlations among transcript and solute levels, that were highly significant in cold acclimated plants, were lost during deacclimation. Other correlations persisted, indicating that after three days of deacclimation, plant metabolism had not completely reverted back to the non-acclimated state. These data provide the basis for further molecular and genetic studies to unravel the regulation of deacclimation.
在低温暴露期间,拟南芥和许多来自温带气候的其他植物会在一个称为冷驯化的过程中提高抗冻性。然而,脱驯化的正确时机和速率同样对植物的适应性和生存至关重要,脱驯化会导致抗冻性丧失并启动生长。虽然冷驯化的分子基础已得到详细研究,但关于脱驯化的信息却少得多。我们已经对10个拟南芥自然生态型在脱驯化条件下的反应进行了表征,这些生态型的抗冻性差异很大。在将冷驯化的植物转移到环境温度后,所有生态型中的糖、脯氨酸和转录水平在三天内急剧下降,而只有耐受性生态型的抗冻性下降。在冷驯化植物中,抗冻性与COR基因表达水平、葡萄糖、果糖和蔗糖含量之间的相关性,以及转录本和溶质水平之间的许多相关性在脱驯化过程中消失了。其他相关性仍然存在,这表明在脱驯化三天后,植物代谢尚未完全恢复到未驯化状态。这些数据为进一步开展分子和遗传学研究以阐明脱驯化的调控机制提供了基础。