Butylated Hydroxytoluene (BHT) Inhibits PIN1 Exocytosis From BFA Compartments in Arabidopsis Roots
Butylated Hydroxytoluene (BHT) Inhibits PIN1 Exocytosis From BFA Compartments in Arabidopsis Roots
复制标题
DOI：
10.3389/fpls.2020.00393
复制
发表时间：
2020-04-08
影响因子：
5.6
通讯作者：
Palme, Klaus
中科院分区：
文献类型：
--
作者：
Paponov, Ivan A.;Budnyk, Vadym;Palme, Klaus
极性定位的PIN形成的（PIN）生长素外排载体的活性有助于形成生长素梯度，指导植物生长，发育和热带反应。PIN蛋白在质膜上的定位和丰度都依赖于PIN通过胞吞和胞吐的运输调节，并且受到许多外部和内部刺激的影响，如活性氧、生长素转运抑制剂、类黄酮和植物激素。在这里，我们研究了内体PIN循环的调节，通过使用Brefeldin A（BFA）测定来研究酚类抗氧化剂紫罗兰醇，丁基化羟基甲苯（BHT），对PIN 1和PIN 2的内吞和胞吐的影响。二叔丁基对甲苯（BHT）是食品和饲料行业中使用最广泛的抗氧化剂之一，因此通常会释放到环境中;然而，二叔丁基对甲苯（BHT）对植物的影响仍然缺乏表征。在BFA处理之前用BHT预孵育拟南芥幼苗强烈增强PIN 1内化到BFA隔室中。BHT和NAA同时作用后，PIN的内化以NAA作用为主，说明BHT作用发生在NAA作用的下游。在BFA处理后用BHT洗涤幼苗防止PIN 1从BFA隔室释放回质膜，表明BHT应用抑制PIN 1胞吐。在BFA处理前用BHT预孵育的幼苗中，PIN 2内化的总体速率不如PIN 1显著，并且PIN 2胞吐不受BHT抑制，表明BHT对PIN 1胞吐具有特异性活性。BHT活性与PIN 1和PIN 2运输的其他潜在刺激的比较[例如，H2 O2（ROS）、盐胁迫、还原型谷胱甘肽（GSH）、二硫苏糖醇（DTT）和类黄酮]表明BHT具有不同于PIN运输的其他调节剂的新活性。研究结果支持BHT作为一个潜在的有趣的药理学工具，解剖PIN贩运和生长素运输。
The activity of polarly localized PIN-FORMED (PIN) auxin efflux carriers contributes to the formation of auxin gradients which guide plant growth, development, and tropic responses. Both the localization and abundance of PIN proteins in the plasma membrane depend on the regulation of PIN trafficking through endocytosis and exocytosis and are influenced by many external and internal stimuli, such as reactive oxygen species, auxin transport inhibitors, flavonoids and plant hormones. Here, we investigated the regulation of endosomal PIN cycling by using a Brefeldin A (BFA) assay to study the effect of a phenolic antioxidant ionol, butylated hydroxytoluene (BHT), on the endocytosis and exocytosis of PIN1 and PIN2. BHT is one of the most widely used antioxidants in the food and feed industries, and as such is commonly released into the environment; however, the effect of BHT on plants remains poorly characterized. Preincubation of Arabidopsis seedlings with BHT before BFA treatment strongly enhanced the internalization of PIN1 into BFA compartments. After the simultaneous application of BHT and NAA, the NAA effect dominated PIN internalization suggesting the BHT effect occurred downstream to that of NAA. Washing seedlings with BHT after BFA treatment prevented the release of PIN1 from BFA compartments back to the plasma membrane, indicating that BHT application inhibited PIN1 exocytosis. Overall rates of PIN2 internalization were less pronounced than those of PIN1 in seedlings pre-incubated with BHT before BFA treatment, and PIN2 exocytosis was not inhibited by BHT, indicating a specific activity of BHT on PIN1 exocytosis. Comparison of BHT activity with other potential stimuli of PIN1 and PIN2 trafficking [e.g., H2O2 (ROS), salt stress, reduced glutathione (GSH), dithiothreitol (DTT), and flavonoids] showed that BHT has a new activity distinct from the activities of other regulators of PIN trafficking. The findings support BHT as a potentially interesting pharmacological tool for dissecting PIN trafficking and auxin transport.