Gansu Provincial Key Laboratory of AridLand Crop Sciences, College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China.
Gansu Provincial Key Laboratory of AridLand Crop Sciences, College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China.
Plant Physiol Biochem. 2020 Oct;155:338-345. doi: 10.1016/j.plaphy.2020.07.011. Epub 2020 Jul 25.
Antifreeze proteins (AFPs) can bind to ice crystals and restrain the formation of larger crystals, a strategy vital to the survival of plants in freezing environments. The BrAFP1 from winter rapeseed cultivars 'Longyou 7' with high cold tolerance was cloned and overexpressed in Arabidopsis. BrAFP1 was localized in the cytoplasm and nucleus. Under cold stress, SOD activity and free proline content were higher, MDA content and relative conductivity were lower in transgenic lines than those in wide-type Arabidopsis. Frostbite of transgenic plants was minimized, whereas frostbite of the Arabidopsis afp1 mutant was severe. Transition of the amino acid at position 17 of BrAFP1 was related to the increased winter survival of the rapeseed cultivar. Cultivars with higher survival rates had a predilection for tyrosine, not tryptophan, at the 17th site in the amino sequence of BrAFP1. Transcription of BrAFP1 was induced more rapidly, and the expression of the gene was also higher, in Longyou 7 than that in Tianyou 4 under cold stress. Overall, the high expression of BrAPF1 confers more cold-tolerance in Longyou 7.
抗冻蛋白（AFPs）可以与冰晶结合，抑制更大晶体的形成，这是植物在冷冻环境中生存的关键策略。耐低温的冬油菜品种“龙游 7”中的 BrAFP1 被克隆并在拟南芥中过表达。BrAFP1 定位于细胞质和细胞核。在冷胁迫下，转基因系的 SOD 活性和游离脯氨酸含量较高，MDA 含量和相对电导率较低。与野生型拟南芥相比，转基因植物的冻伤最小化，而拟南芥 afp1 突变体的冻伤严重。BrAFP1 第 17 位氨基酸的突变与油菜品种冬季存活率的提高有关。存活率较高的品种在 BrAFP1 氨基酸序列的第 17 位更喜欢酪氨酸而不是色氨酸。在冷胁迫下，龙游 7 中转录 BrAFP1 的速度更快，基因表达也更高。总的来说，BrAPF1 的高表达赋予了龙游 7 更高的耐寒性。
