Alloxan disintegrates the plant cytoskeleton and suppresses mlo-mediated powdery mildew resistance.
Alloxan disintegrates the plant cytoskeleton and suppresses mlo-mediated powdery mildew resistance.
复制标题
DOI：
10.1093/pcp/pcz216
复制
发表时间：
2019-11
影响因子：
4.9
通讯作者：
Hongpo Wu;Weiwei Zhang;M. Schuster;M. Moch;R. Windoffer;G. Steinberg;C. Staiger;R. Panstruga
中科院分区：
文献类型：
--
作者：
Hongpo Wu;Weiwei Zhang;M. Schuster;M. Moch;R. Windoffer;G. Steinberg;C. Staiger;R. Panstruga
Mlo基因的隐性遗传突变等位基因（mlo）赋予被子植物对白粉病病原菌的广谱渗透抗性。尽管已知mlo抗性需要一些成分，但这种免疫类型的详细分子机制仍然难以捉摸。在本研究中，我们确定了四氧嘧啶（5，5-二羟基嘧啶-2，4，6-三酮）和它的一些结构类似物作为单子叶大麦（大麦）和双子叶拟南芥中的mlo介导的抗性的化学抑制剂。除了mlo抗性，四氧嘧啶损害拟南芥的非宿主抗性。组织学分析揭示，该化学物质减少了真菌试图渗透部位的胼胝质沉积和过氧化氢积累。荧光显微镜显示，四氧嘧啶干扰细胞器（过氧化物酶体，内体和内质网）的运动和病原体触发的PEN 1/SYP 121 t-SNARE蛋白的再分布。这些细胞缺陷可能是四氧嘧啶处理后肌动蛋白丝和微管解体的结果。与动物细胞中的情况类似，四氧嘧啶引起拟南芥子叶和莲座叶中活性氧（ROS）的暂时积累。我们的研究结果表明，四氧嘧啶可能会通过诱导早期短暂的ROS爆发破坏细胞骨架结构，进一步导致对植物免疫至关重要的分子和细胞过程的失败。
Recessively inherited mutant alleles of Mlo genes (mlo) confer broad-spectrum penetration resistance to powdery mildew pathogens in angiosperm plants. Although a few components are known to be required for mlo resistance, the detailed molecular mechanism underlying this type of immunity remains elusive. In the present study, we identified alloxan (5,5-dihydroxyl pyrimidine-2,4,6-trione) and some of its structural analogs as chemical suppressors of mlo-mediated resistance in monocotyledonous barley (Hordeum vulgare) and dicotyledonous Arabidopsis thaliana. Apart from mlo resistance, alloxan impairs non-host resistance in Arabidopsis. Histological analysis unraveled that the chemical reduces callose deposition and hydrogen peroxide accumulation at attempted fungal penetration sites. Fluorescence microscopy revealed that alloxan interferes with the motility of cellular organelles (peroxisomes, endosomes and the endoplasmic reticulum) and the pathogen-triggered redistribution of the PEN1/SYP121 t-SNARE protein. These cellular deficits are likely the consequence of disassembly of actin filaments and microtubules upon alloxan treatment. Similar to the situation in animal cells, alloxan elicited the temporary accumulation of reactive oxygen species (ROS) in cotyledons and rosette leaves of Arabidopsis plants. Our results suggest that alloxan may destabilize cytoskeletal architecture via induction of an early transient ROS burst, further leading to the failure of molecular and cellular processes that are critical for plant immunity.