Wu Wangze, Yang Haobo, Xing Peng, Dong Yun, Shen Juan, Wu Guofan, Zheng Sheng, Da Lingling, He Jiangtao, Wu Yujun
College of Life Sciences, Northwest Normal University, Lanzhou, China.
Crop Research Institute, Gansu Academy of Agriculture Sciences, Lanzhou, China.
Front Genet. 2022 Apr 26;13:871825. doi: 10.3389/fgene.2022.871825. eCollection 2022.
Winter rapeseed ( L.) is an important oilseed crop in northwest China. Freezing stress severely limits its production and geographical distribution, and frequent extreme freezing events caused by climate change are increasing the chances of winter freeze-injury. However, the underlying mechanism of response to freezing stress remains elusive. Here, genome (v3.0) was used as a reference for the comparative transcriptomic analysis of Longyou 6 and Tianyou 2 (strong and weak cold tolerance, respectively) under different freezing stress. Before and after freezing stress, 5,982 and 11,630 unique differentially expressed genes (DEGs) between two cultivars were identified, respectively. After freezing stress, the GO terms in Tianyou 2 were mainly involved in "macromolecule biosynthetic process", and those in Longyou 6 were involved in "response to stimulus" and "oxidoreductase activity". Morphological and physiological results indicated that Longyou 6 retained a higher basal freezing resistance than Tinayou 2, and that cold acclimation could strengthen the basal freezing resistance. Freezing stress could activate the MAPK signal cascades, and the phosphorylation level of Longyou 6 showed a higher increase in response to freezing treatment than Tianyou 2. Based on our findings, it was speculated that the cell membrane of perceives external signals under freezing stress, which are then transmitted to the nucleus through the cold-activated MAPK cascades and Ca-related protein kinase pathway, thus leading to activation of downstream target genes to enhance the freezing resistance of
冬油菜（L.）是中国西北地区一种重要的油料作物。冻害胁迫严重限制了其产量和地理分布，气候变化导致的频繁极端冻害事件增加了冬季冻害的发生几率。然而，其对冻害胁迫响应的潜在机制仍不清楚。在此，利用基因组（v3.0）作为参考，对陇油6号和天油2号（分别具有强抗寒性和弱抗寒性）在不同冻害胁迫下进行比较转录组分析。在冻害胁迫前后，分别在两个品种间鉴定出5982个和11630个独特的差异表达基因（DEGs）。冻害胁迫后，天油2号中的GO术语主要参与“大分子生物合成过程”，而陇油6号中的GO术语参与“对刺激的响应”和“氧化还原酶活性”。形态学和生理学结果表明，陇油6号比天油2号保留了更高的基础抗冻性，并且低温驯化可以增强基础抗冻性。冻害胁迫可激活MAPK信号级联反应，陇油6号在冷冻处理后的磷酸化水平比天油2号有更高的升高。基于我们的研究结果，推测在冻害胁迫下冬油菜的细胞膜感知外部信号，然后通过冷激活的MAPK级联反应和钙相关蛋白激酶途径传递到细胞核，从而导致下游靶基因的激活以增强其抗冻性。
