MSD2, an apoplastic Mn-SOD, contributes to root skotomorphogenic growth by modulating ROS distribution in Arabidopsis
MSD2, an apoplastic Mn-SOD, contributes to root skotomorphogenic growth by modulating ROS distribution in Arabidopsis
复制标题
MSD2 是一种质外体 Mn-SOD，通过调节拟南芥中 ROS 的分布来促进根的暗形态生长
DOI：
10.1016/j.plantsci.2022.111192
复制
发表时间：
2022-01-21
期刊：
影响因子：
5.2
通讯作者：
Lee, Yuree
中科院分区：
文献类型：
--
作者：
Chen, Huize;Lee, Jinsu;Lee, Yuree
活性氧（Reactive oxygen species，ROS）作为第二信使在植物的多种生理过程中发挥着重要作用。由于其氧化性质，ROS也可能是有害的。因此，ROS的产生和体内平衡受到多种酶的严格控制。膜定位的NADPH氧化酶在发育和胁迫反应中产生ROS，但它们在质外体中产生超氧化物（O2 '-）的代谢途径知之甚少，拟南芥质外体超氧化物歧化酶（SOD）的身份未知。在这里，我们表明，一个假定的锰超氧化物歧化酶，MSD 2的分泌，并具有超氧化物歧化酶的活性，可以通过硝化酪氨酸68抑制。MSD 2在根中的表达具有光依赖性，表明MSD 2可能在光暗转换过程中对根中的ROS代谢起作用。根的结构是由ROS分布，表现出相反的梯度H2 O2和O2 '-，这确实是改变黄化msd 2突变体，并伴随着在分化的开始变化。这些结果为我们理解ROS代谢提供了一个缺失的环节，并表明MSD 2通过调节ROS分布在根的skotomorphogenesis中发挥作用，从而在植物生长发育中发挥关键作用。
Reactive oxygen species (ROS) play essential roles as a second messenger in various physiological processes in plants. Due to their oxidative nature, ROS can also be harmful. Thus, the generation and homeostasis of ROS are tightly controlled by multiple enzymes. Membrane-localized NADPH oxidases are well known to generate ROS during developmental and stress responses, but the metabolic pathways of the superoxide (O2'- ) generated by them in the apoplast are poorly understood, and the identity of the apoplastic superoxide dismutase (SOD) is unknown in Arabidopsis. Here, we show that a putative manganese SOD, MSD2 is secreted and possesses a SOD activity that can be inhibited by nitration at tyrosine 68. The expression of MSD2 in roots is light conditiondependent, suggesting that MSD2 may act on ROS metabolism in roots during the light-to-dark transition. Root architecture is governed by ROS distribution that exhibits opposite gradient of H2O2 and O2'-, which is indeed altered in etiolated msd2 mutants and accompanied by changes in the onset of differentiation. These results provide a missing link in our understanding of ROS metabolism and suggest that MSD2 plays a role in root skotomorphogenesis by regulating ROS distribution, thereby playing a pivotal role in plant growth and development.