A Functional Alternative Oxidase Modulates Plant Salt Tolerance in Physcomitrella patens
A Functional Alternative Oxidase Modulates Plant Salt Tolerance in Physcomitrella patens
复制标题
一种功能性替代氧化酶调节小立碗藓植物耐盐性
DOI：
10.1093/pcp/pcz099
复制
发表时间：
2019
影响因子：
4.9
通讯作者：
Lin Honghui
中科院分区：
文献类型：
--
作者：
Wu Guochun;Li Sha;Li Xiaochuan;Liu Yunhong;Zhao Shuangshuang;Liu Baohui;Zhou Huapeng;Lin Honghui
交替氧化酶（AOX）参与线粒体功能和氧化还原平衡，在植物生长和逆境响应中起着重要作用。然而，它在非种子植物中的生物学功能还没有得到很好的表征。本文报道了AOX参与藓类植物小立碗藓（Physcomitrella patens，P. patens）耐盐性的调节。AOX是高度保守的，定位于线粒体中。patens。我们观察到PpAOX可以挽救拟南芥（Arabidopsis thaliana，Arabidopsis）中受损的抗氰化物（CN）交替（Alt）呼吸途径。patens。利用同源重组技术，获得了PpAOOX超表达株系（PpAOOX），在盐胁迫下，PpAOOX植株表现出较高的Alt呼吸和较低的总活性氧积累。引人注目的是，我们观察到PpAOXOX植物表现出耐盐性下降。PpAOX的过表达扰乱了叶绿体的氧化还原平衡。同时，与野生型（WT）展叶侧耳相比，PpAOXOX植株的叶绿体结构受到不利影响。我们发现PpAOXOX植株的光合活性也比WT低。总之，我们的工作揭示了AOX参与植物耐盐性。在挑战性条件下，线粒体和叶绿体之间存在功能联系。
Alternative oxidase (AOX) has been reported to be involved in mitochondrial function and redox homeostasis, thus playing an essential role in plant growth as well as stress responses. However, its biological functions in nonseed plants have not been well characterized. Here, we report that AOX participates in plant salt tolerance regulation in mossPhyscomitrella patens(P. patens). AOX is highly conserved and localizes to mitochondria inP. patens. We observed thatPpAOXrescued the impaired cyanide (CN)-resistant alternative (Alt) respiratory pathway inArabidopsis thaliana(Arabidopsis)aox1amutant.PpAOXtranscription and Alt respiration were induced upon salt stress inP. patens. Using homologous recombination, we generatedPpAOX-overexpressing lines (PpAOXOX).PpAOXOX plants exhibited higher Alt respiration and lower total reactive oxygen species accumulation under salt stress condition. Strikingly, we observed thatPpAOXOX plants displayed decreased salt tolerance. Overexpression ofPpAOXdisturbed redox homeostasis in chloroplasts. Meanwhile, chloroplast structure was adversely affected inPpAOXOX plants in contrast to wild-type (WT)P. patens. We found that photosynthetic activity inPpAOXOX plants was also lower compared with that in WT. Together, our work revealed that AOX participates in plant salt tolerance inP. patensand there is a functional link between mitochondria and chloroplast under challenging conditions.