Endosome-Associated CRT1 Functions Early in Resistance Gene-Mediated Defense Signaling in Arabidopsis and Tobacco
Endosome-Associated CRT1 Functions Early in Resistance Gene-Mediated Defense Signaling in Arabidopsis and Tobacco
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DOI：
10.1105/tpc.109.071662
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发表时间：
2010-03-01
期刊：
影响因子：
11.6
通讯作者：
Klessig, Daniel F.
中科院分区：
文献类型：
--
作者：
Kang, Hong-Gu;Oh, Chang-Sik;Klessig, Daniel F.
抗性基因介导的免疫在广泛的植物中提供了对病原体侵染的保护。对拟南芥突变体的遗传筛选表明，该突变体不能识别先前发现的萝卜皱缩病毒CRT1，它是GHKL ATPase/KK超家族的成员之一。在这里，我们证明了CRT1与来自不同结构类别的各种抗性蛋白相互作用，当这些抗性蛋白被激活时，这种相互作用被破坏。拟南芥突变体crt1-2crh1-1缺乏CRT1及其最接近的同源基因，对无毒的丁香假单胞菌和阿拉伯灰霉病菌表现出折衷抗性。此外，在抑制CRT1同源基因表达的本氏烟草中，与抗性相关的过敏性细胞死亡被抑制(S)。因此，CRT1似乎是耐药基因免疫的一般因素。由于在crt1-2crh1-1植物中，由无毒丁香疫霉引起的细胞内钙的升高受到抑制，而在CRT1沉默的本氏新月球藻中，NT MEK2(DD)引发的细胞死亡不受影响，因此CRT1可能在这一途径的早期发挥作用。全基因组转录组分析导致了CRT1相关基因的鉴定，其中许多基因与运输过程、对(A)生物胁迫的反应以及内膜系统有关。共聚焦显微镜和亚细胞分离显示CRT1定位于内体样囊泡，提示抗性蛋白激活/信号转导的关键过程发生在这个亚细胞室。
Resistance gene-mediated immunity confers protection against pathogen infection in a wide range of plants. A genetic screen for Arabidopsis thaliana mutants compromised for recognition of turnip crinkle virus previously identified CRT1, a member of the GHKL ATPase/kinase superfamily. Here, we demonstrate that CRT1 interacts with various resistance proteins from different structural classes, and this interaction is disrupted when these resistance proteins are activated. The Arabidopsis mutant crt1-2 crh1-1, which lacks CRT1 and its closest homolog, displayed compromised resistance to avirulent Pseudomonas syringae and Hyaloperonospora arabidopsidis. Additionally, resistance-associated hypersensitive cell death was suppressed in Nicotiana benthamiana silenced for expression of CRT1 homolog(s). Thus, CRT1 appears to be a general factor for resistance gene-mediated immunity. Since elevation of cytosolic calcium triggered by avirulent P. syringae was compromised in crt1-2 crh1-1 plants, but cell death triggered by Nt MEK2(DD) was unaffected in CRT1-silenced N. benthamiana, CRT1 likely functions at an early step in this pathway. Genome-wide transcriptome analysis led to identification of CRT1-Associated genes, many of which are associated with transport processes, responses to (a) biotic stress, and the endomembrane system. Confocal microscopy and subcellular fractionation revealed that CRT1 localizes to endosome-like vesicles, suggesting a key process in resistance protein activation/signaling occurs in this subcellular compartment.