Volatile-Mediated Killing of Arabidopsis thaliana by Bacteria Is Mainly Due to Hydrogen Cyanide
Volatile-Mediated Killing of Arabidopsis thaliana by Bacteria Is Mainly Due to Hydrogen Cyanide
复制标题
DOI：
10.1128/aem.01968-10
复制
发表时间：
2011-02-01
影响因子：
4.4
通讯作者：
Weisskopf, Laure
中科院分区：
文献类型：
--
作者：
Blom, Dirk;Fabbri, Carlotta;Weisskopf, Laure
挥发性细菌对植物生长的影响是有据可查的，从6倍的植物促进到植物死亡，各种不同的影响都有报道。然而，人们对引起这些影响的化合物的特性或涉及植物生长变化的机制知之甚少。我们假设氰化氢(HCN)是导致观察到的某些菌株的挥发性毒性的主要因素。使用一组在氰化物发生方面不同的环境和临床菌株，以及一个明确的HCN阴性突变体，我们证明了细菌HCN在很大程度上解释了在某些细菌挥发物存在的情况下培养拟南芥时观察到的有害影响。与铜绿假单胞菌PAO1相比，环境菌株PUPa3的产氰量和对植物生长的抑制程度较低。群体感应缺陷突变体Vioraceum CV0、P.铜绿假单胞菌PAO1和P.铜绿假单胞菌PUPa3不仅表现出减少HCN的产生，而且显著降低了挥发性物质介导的植物毒性。给植物提供清除活性氧的化合物和过量表达交替氧化酶AOX1a的双重处理显著降低了挥发性物质介导的毒性。这表明氧化胁迫是导致植物在暴露于有毒细菌挥发物后死亡的生理变化中的一个关键过程。
The volatile-mediated impact of bacteria on plant growth is well documented, and contrasting effects have been reported ranging from 6-fold plant promotion to plant killing. However, very little is known about the identity of the compounds responsible for these effects or the mechanisms involved in plant growth alteration. We hypothesized that hydrogen cyanide (HCN) is a major factor accounting for the observed volatile-mediated toxicity of some strains. Using a collection of environmental and clinical strains differing in cyanogenesis, as well as a defined HCN-negative mutant, we demonstrate that bacterial HCN accounts to a significant extent for the deleterious effects observed when growing Arabidopsis thaliana in the presence of certain bacterial volatiles. The environmental strain Pseudomonas aeruginosa PUPa3 was less cyanogenic and less plant growth inhibiting than the clinical strain P. aeruginosa PAO1. Quorum-sensing deficient mutants of C. violaceum CV0, P. aeruginosa PAO1, and P. aeruginosa PUPa3 showed not only diminished HCN production but also strongly reduced volatile-mediated phytotoxicity. The double treatment of providing plants with reactive oxygen species scavenging compounds and overexpressing the alternative oxidase AOX1a led to a significant reduction of volatile-mediated toxicity. This indicates that oxidative stress is a key process in the physiological changes leading to plant death upon exposure to toxic bacterial volatiles.