CATALASE2 functions for seedling postgerminative growth by scavenging H2O2 and stimulating ACX2/3 activity in Arabidopsis
CATALASE2 functions for seedling postgerminative growth by scavenging H2O2 and stimulating ACX2/3 activity in Arabidopsis
复制标题
CATALASE2 通过清除 H2O2 并刺激拟南芥中的 ACX2/3 活性来促进幼苗发芽后生长
DOI：
10.1111/pce.13031
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发表时间：
2017-11-01
影响因子：
7.3
通讯作者：
Lu, Ying-Tang
中科院分区：
文献类型：
--
作者：
Liu, Wen-Cheng;Han, Tong-Tong;Lu, Ying-Tang
增加脂肪酸氧化是必不可少的早期萌发后生长的幼苗，但高水平的过氧化氢产生的氧化可诱导氧化胁迫。过氧化氢酶（CAT）是否以及如何在幼苗生长过程中微调H2 O2稳态的功能尚不清楚。在这里，我们报告CAT 2功能在早期幼苗生长。与野生型相比，cat 2 -1突变体，具有升高的H2 O2水平，表现出减少根伸长蔗糖（Suc）-无培养基，模仿土壤没有外源糖供应。用H2 O2清除剂碘化钾处理拯救了cat 2 -1的突变表型。与野生型相比，cat 2 -1突变体在无蔗糖培养基上生长时对CAT抑制剂3-amino-1，2，4-triazole根伸长不敏感，表明CAT 2通过改变H2 O2积累来调节早期幼苗生长。此外，与cat 2 -1一样，酰基辅酶A氧化酶（ACX）双突变体acx 2 -1 acx 3 -6表现出抑制根伸长，表明CAT 2通过调节ACX活性在早期幼苗生长中发挥作用，因为该活性在cat 2 -1中受到抑制。事实上，ACX活性下降和短根的cat 2 -1幼苗生长在Suc-无培养基中拯救过表达ACX 3。这些发现表明CAT 2通过清除H2 O2和刺激ACX 2/3活性在早期幼苗生长中起作用。
Increased fatty acid -oxidation is essential for early postgerminative growth in seedlings, but high levels of H2O2 produced by -oxidation can induce oxidative stress. Whether and how catalase (CAT) functions in fine-tuning H2O2 homeostasis during seedling growth remain unclear. Here, we report that CAT2 functions in early seedling growth. Compared to the wild type, the cat2-1 mutant, with elevated H2O2 levels, exhibited reduced root elongation on sucrose (Suc)-free medium, mimicking soils without exogenous sugar supply. Treatment with the H2O2 scavenger potassium iodide rescued the mutant phenotype of cat2-1. In contrast to the wild type, the cat2-1 mutant was insensitive to the CAT inhibitor 3-amino-1,2,4-triazole in terms of root elongation when grown on Suc-free medium, suggesting that CAT2 modulates early seedling growth by altering H2O2 accumulation. Furthermore, like cat2-1, the acyl-CoA oxidase (ACX) double mutant acx2-1 acx3-6 showed repressed root elongation, suggesting that CAT2 functions in early seedling growth by regulating ACX activity, as this activity was inhibited in cat2-1. Indeed, decreased ACX activity and short root of cat2-1 seedlings grown on Suc-free medium were rescued by overexpressing ACX3. Together, these findings suggest that CAT2 functions in early seedling growth by scavenging H2O2 and stimulating ACX2/3 activity.