Long-chain base kinase1 affects freezing tolerance in Arabidopsis thaliana
Long-chain base kinase1 affects freezing tolerance in Arabidopsis thaliana
复制标题
长链碱基激酶1影响拟南芥的冷冻耐受性
DOI：
10.1016/j.plantsci.2017.03.009
复制
发表时间：
2017-06-01
期刊：
影响因子：
5.2
通讯作者：
Shi, Yiting
中科院分区：
文献类型：
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作者：
Huang, Xiaozhen;Zhang, Yao;Shi, Yiting
长链碱基激酶（LCBK）磷酸化鞘脂衍生的长链碱基脂质并参与植物逆境反应的调节。在这里，我们分离了一种新的拟南芥突变体 lcbk1-2，它对冷冻温度极其敏感，无论有或没有冷驯化。生理测定表明，与野生型相比，lcbk1-2突变体中渗透调节剂（脯氨酸和可溶性糖）的浓度和超氧化物歧化酶的活性显着降低。此外，无论有或没有冷处理，lcbk1-2突变体中活性氧（ROS）的平衡都被破坏，与此一致，基因表达谱分析表明，lcbk1-2突变体中冷反应性ROS清除基因的表达显着降低。 lcbk1-2 突变体中与植物耐冻性相关的膜脂相关基因的表达也受到损害。此外，过度表达 LCBK1 的转基因品系显示出由于渗透剂过度积累而增强的冷冻耐受性。总的来说，我们的结果表明，LCBK1 在拟南芥中作为一种新型的冷冻耐受性正调节因子发挥作用，并可能参与渗透剂的积累、ROS 稳态和脂质代谢的调节。
Long-chain base kinases (LCBKs) phosphorylate sphingolipid-derived long-chain base lipids and participate in the regulation of stress responses in plants. Here, we isolated a novel Arabidopsis thaliana mutant, lcbk1-2, which was extremely sensitive to freezing temperatures with or without cold acclimation. Physiological assays revealed that concentrations of osmolytes (proline and soluble sugars) and the activity of superoxide dismutase were significantly decreased in the lcbk1-2 mutant, compared with wild type. Also, the balance of reactive oxygen species (ROS) was disrupted in the lcbk1-2 mutant with or without cold treatment and, consistent with this, gene expression profiling analysis showed that the expression of cold-responsive ROS-scavenging genes was substantially decreased in the lcbk1-2 mutant. The expression of membrane lipid-related genes, which are linked to freezing tolerance in plants, was also impaired in the lcbk1-2 mutant. Furthermore, transgenic lines overexpressing LCBK1 showed enhanced freezing tolerance with over-accumulation of osmolytes. Collectively, our results suggested that LCBK1 functions as a novel positive regulator of freezing tolerance in Arabidopsis and may participate in the accumulation of osmolytes, the regulation of ROS homeostasis and lipid metabolism.